Polymer and polymeric luminescent element comprising the same

ABSTRACT

A polymer characterized by comprising repeating units represented by the following formula (1) and having a number-average molecular weight, in terms of polystyrene, of 10 3  to 10 8 . 
                         
(In the formula, R 1  represents hydrogen, alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino, silyl, substituted silyl, silyloxy, substituted silyloxy, monovalent heterocyclic group, or halogeno; and rings D and E each represents an optionally substituted aromatic ring.)

TECHNICAL FIELD

The present invention relates to a polymer and a method for producingthe same, an ink composition that contains the polymer, and a polymericlight-emitting device (hereinafter sometimes referred to as polymericLED) using the polymer.

BACKGROUND ART

Various types of high-molecular-weight light-emitting materials orcharge transport materials are being examined, because, unlikelow-molecular-weight light-emitting materials or charge transportmaterials, they are soluble in solvents and can form a light-emittinglayer or charge transport layer in a light-emitting device, depending onthe coating method employed. Of such materials, polyphenylenevinylenederivatives, polyfluorene derivatives and polyphenylene derivatives arewell-known.

DISCLOSURE OF THE INVENTION

The object of this invention is to provide a novel polymer usable as alight-emitting material, charge transport material, or the like, amethod for producing the same, and a polymeric light-emitting deviceusing the polymer.

After directing tremendous effort toward the above described subject,the present inventors have found that a polymer that includes arepeating unit represented by the following formula (1):

and having a number-average molecular weight, in terms of polystyrene,of 10³ to 10⁸ can applied to a light-emitting material, charge transportmaterial or the like and have finally accomplished this invention.

BEST MODE FOR CARRYING OUT THE INVENTION

In the above formula (1), rings D and E each represent an aromatic ring.

Examples of such aromatic rings include: aromatic hydrocarbon rings suchas benzene, naphthalene, anthracene, phenanthrene, pyrene, perylene,tetracene and pentacene rings; and heteroaromatic rings such aspyridine, pyrimidine, pyridazine, pyrazine, quinoline, isoquinoline,quinoxaline, quinazoline, acridine, phenanthroline, thiophene,benzothiophene, dibenzothiophene, thiophenoxide, benzothiophenoxide,dibenzothiophenoxide, thiophenedioxide, benzothiophenedioxide,dibenzothiophenedioxide, furan, benzofuran, dibenzofuran, pyrrole,indole, dibenzopyrrole, silole, benzosilole, dibenzosilole, borole,benzoborole and dibenzoborole rings. Of these aromatic rings, aromatichydrocarbon rings are preferable, and benzene, naphthalene andanthracene rings are particularly preferable.

The rings D and E optionally have a substituent selected from the groupconsisting of alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio,arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino,substituted amino, silyl, substituted silyl, silyloxy and substitutedsilyloxy groups, halogen atoms, acyl, acyloxy, imino, amide, imide,monovalent heterocyclic, carboxyl, substituted carboxyl and cyanogroups.

The above described alkyl groups may be straight-chain, branched-chainor cyclic alkyl groups. The number of carbons that each of the alkylgroups has is usually about 1 to 20 and preferably 3 to 20. Specificexamples of the alkyl groups include methyl, ethyl, propyl, i-propyl,butyl, i-butyl, t-butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl,2-ethylhexyl, nonyl, decyl, 3,7-dimethyloctyl, lauryl, trifluoromethyl,pentafluoroethyl, perfluorobutyl, perfluorohexyl and perfluorooctylgroups. Preferable are pentyl, hexyl, octyl, 2-ethylhexyl, decyl and3,7-dimethyloctyl.

The above described alkoxy groups may be straight-chain, branched-chainor cyclic alkoxy groups. The number of carbons that each of the alkoxygroups has is usually about 1 to 20 and preferably 3 to 20. Specificexamples of the alkoxy groups include methoxy, ethoxy, propyloxy,i-propyloxy, butoxy, i-butoxy, t-butoxy, pentyloxy, hexyloxy,cyclohexyloxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy,3,7-dimethyloctyloxy, lauryloxy, trifluoromethoxy, pentafluoroethoxy,perfluorobutoxy, perfluorohexyl, perfluoroctyl, methoxymethyloxy and2-methoxyethyloxy. Of these groups, preferable are pentyloxy, hexyloxy,octyloxy, 2-ethylhexyloxy, decyloxy and 3,7-dimethyloctyloxy groups.

The above described alkylthio groups may be straight-chain,branched-chain or cyclic alkylthio groups. The number of carbons thateach of the alkylthio groups has is usually about 1 to 20 and preferably3 to 20. Specific examples of the alkylthio groups include methylthio,ethylthio, propylthio, i-propylthio, butylthio, i-butylthio,t-butylthio, pentylthio, hexylthio, cyclohexylthio, heptylthio,octylthio, 2-ethylhexylthio, nonylthio, decylthio,3,7-dimethyloctylthio, laurylthio and trifluoromethylthio groups. Ofthese groups, preferable are pentylthio, hexylthio, octylthio,2-ethylhexylthio, decylthio and 3,7-dimethyloctylthio groups.

The number of carbons that each of the above aryl groups has is usuallyabout 6 to 60 and preferably 7 to 48. Examples of the aryl groupsinclude phenyl, C₁–C₁₂ alkoxyphenyl (“C₁–C₁₂” indicates the number ofcarbons the aryl group has is 1 to 12 and the same is true hereafter),C₁–C₁₂ alkylphenyl, 1-naphthyl, 2-naphthyl, 1-anthracenyl,2-anthracenyl, 9-anthracenyl and pentafluorophenyl groups. Of these arylgroups, C₁–C₁₂ alkoxyphenyl and C₁–C₁₂ alkylphenyl groups arepreferable. The term “aryl group” means an atomic group derived from anaromatic hydrocarbon by removal one of hydrogens on the aromaticnucleus. The aromatic hydrocarbons includes those having a condensedring and those formed by combining two or more independent benzene ringsor condensed rings directly or via a group such as vinylene.

Specific examples of C₁–C₁₂ alkoxy groups include methoxy, ethoxy,propyloxy, i-propyloxy, butoxy, i-butoxy, t-butoxy, pentyloxy, hexyloxy,cyclohexyloxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy,3,7-dimethyloctyloxy and lauryloxy groups.

Specific examples of C₁–C₁₂ alkyl groups include methyl, ethyl, propyl,i-propyl, butyl, i-butyl, t-butyl, pentyl, hexyl, cyclohexyl, heptyl,octyl, 2-ethylhexyl, nonyl, decyl, 3,7-dimethyloctyl and lauryl groups.

The number of carbons that each of the above described aryloxy groupshas is usually about 6 to 60 and preferably 7 to 48. Examples of thearyloxy groups include phenoxy, C₁–C₁₂ alkoxyphenoxy, C₁–C₁₂alkylphenoxy, 1-naphthyloxy, 2-naphthyloxy and pentafluorophenyloxygroups. Of these groups, C₁–C₁₂ alkoxyphenoxy and C₁–C₁₂ alkylphenoxygroups are preferable.

The number of carbons that each of the above described arylthio groupshas is usually about 6 to 60 and preferably 7 to 48. Examples of thearylthio groups include phenylthio, C₁–C₁₂ alkoxyphenylthio, C₁–C₁₂alkylphenylthio, 1-naphthylthio, 2-naphthylthio andpentafluorophenylthio groups. Of these arylthio groups, C₁–C₁₂alkoxyphenylthio and C₁–C₁₂ alkylphenylthio groups are preferable.

The number of carbons that each of the above described arylalkyl groupshas is usually about 7 to 60 and preferably 7 to 48. Examples of thearylalkyl groups include: phenyl-(C₁–C₁₂)-alkyl groups such asphenylmethyl, phenylethyl, phenylbutyl, phenylpentyl, phenylhexyl,phenylheptyl and phenyloctyl; C₁–C₁₂ alkoxyphenyl-(C₁–C₁₂)-alkyl groups;C₁–C₁₂ alkylphenyl-(C₁–C₁₂)-alkyl groups; 1-naphtyl-(C₁–C₁₂)-alkylgroups; and 2-naphtyl-(C₁–C₁₂)-alkyl groups. Of these arylalkyl groups,C₁–C₁₂ alkoxyphenyl-(C₁–C₁₂)-alkyl groups and C₁–C₁₂alkylphenyl-(C₁–C₁₂)-alkyl groups. are preferable.

The number of carbons that each of the above described arylalkoxy groupshas is usually about 7 to 60 and preferably 7 to 48. Examples of thearylalkoxy groups include: phenyl-(C₁–C₁₂)-alkoxy groups such asphenylmethoxy, phenylethoxy, phenylbutoxy, phenylpentyloxy,phenylhexyloxy, phenylheptyloxy and phenyloctyloxy; C₁–C₁₂alkoxyphenyl-(C₁–C₁₂)-alkoxy groups; C₁–C₁₂ alkylphenyl-(C₁–C₁₂)-alkoxygroups; 1-naphtyl-(C₁–C₁₂)-alkoxy groups; and 2-naphtyl-(C₁–C₁₂)-alkoxygroups. Of these arylalkoxy groups, C₁–C₁₂ alkoxyphenyl-(C₁–C₁₂)-alkoxygroups and C₁–C_(l2) alkylphenyl-(C₁–C₁₂)-alkoxy groups are preferable.

The number of carbons that each of the above described arylalkylthiogroups has is usually about 7 to 60 and preferably 7 to 48. Examples ofthe arylalkylthio groups include: phenyl-(C₁–C₁₂)-alkylthio groups;C₁–C₁₂ alkoxyphenyl-(C₁–C₁₂)-alkylthio groups; C₁–C₁₂alkylphenyl-(C₁–C₁₂)-alkylthio groups; 1-naphtyl-(C₁–C₁₂)-alkylthiogroups; and 2-naphtyl-(C₁–C₁₂)-alkylthio groups. Of these arylalkoxygroups, C₁–C₁₂ alkoxyphenyl-(C₁–C₁₂)-alkylthio groups and C₁–C₁₂alkylphenyl-(C₁–C₁₂)-alkylthio groups are preferable.

The number of carbons that each of the above described arylalkenylgroups has is usually about 8 to 60 and preferably 8 to 48. Examples ofthe arylalkenyl groups include: phenyl-(C₂–C₁₂)-alkenyl groups; C₁–C₁₂alkoxyphenyl-(C₂–C₁₂)-alkenyl groups; C₁–C₁₂alkylphenyl-(C₂–C₁₂)-alkenyl groups; 1-naphtyl-(C₂–C₁₂)-alkenyl groups;and 2-naphtyl-(C₂–C₁₂)-alkenyl groups. Of these arylalkenyl groups,C₁–C₁₂ alkoxyphenyl-(C₂–C₁₂)-alkenyl groups and C₁–C₁₂alkylphenyl-(C₂–C₁₂)-alkenyl groups are preferable.

The number of carbons that each of the above described arylalkynylgroups has is usually about 8 to 60 and preferably 8 to 48. Examples ofthe arylalkynyl groups include: phenyl-(C₂–C₁₂)-alkynyl groups; C₁–C₁₂alkoxyphenyl-(C₂–C₁₂)-alkynyl groups; C₁–C₁₂alkylphenyl-(C₂–C₁₂)-alkynyl groups; 1-naphtyl-(C₂–C₁₂)-alkynyl groups;and 2-naphtyl-(C₂–C₁₂)-alkynyl groups. Of these arylalkynyl groups,C₁–C₁₂ alkoxyphenyl-(C₂–C₁₂)-alkynyl groups and C₁–C₁₂alkylphenyl-(C₂–C₁₂)-alkynyl groups are preferable.

The above described substituted amino groups mean amino groupssubstituted by one or two groups selected from the group consisting ofalkyl, aryl, arylalkyl and monovalent heterocyclic groups. The number ofcarbons that each of the substituted amino groups has is usually about 1to 60 and preferably 2 to 48.

Examples of the substituted amino groups include methylamino,dimethylamino, ethylamino, diethylamino, propylamino, dipropylamino,i-propylamino, diisopropylamino, butylamino, i-butylamino, t-butylamino,pentylamino, hexylamino, cyclohexylamino, heptylamino, octylamino,2-ethylhexylamino, nonylamino, decylamino, 3,7-dimethyloctylamino,laurylamino, cyclopentylamino, dicyclopentylamino, cyclohexylamino,dicyclohexylamino, pyrrolidyl, piperidyl, ditrifluoromethylamino,phenylamino, diphenylamino, C₁–C₁₂ alkoxyphenylamino,di((C₁–C₁₂)-alkoxyphenyl)amino, di((C₁–C₁₂)-alkylphenyl)amino,1-naphthylamino, 2-naphthylamino, pentafluorophenylamino, pyridylamino,pyridazinylamio, pyrimidylamino, pyrazylamino, triazylamino,phenyl-(C₁–C₁₂)-alkylamino, C₁–C₁₂ alkoxyphenyl-(C₁–C₁₂)-alkylamino,C₁–C₁₂ alkylphenyl-(C₁–C₁₂)-alkylamino,di((C₁–C₁₂)-alkoxyphenyl-(C₁–C₁₂)-alkyl)amino,di((C₁–C₁₂)-alkylphenyl-(C₁–C₁₂)-alkyl)amino,1-naphthyl-(C₁–C₁₂)-alkylamino, 2-naphthyl-(C₁–C₁₂)-alkylamino andcarbazoyl groups.

The above described substituted silyl groups mean silyl groupssubstituted by one, two or three groups selected from the groupconsisting of alkyl, aryl, arylalkyl and monovalent heterocyclic groups.The number of carbons that each of the substituted silyl groups has isusually about 1 to 60 and preferably 3 to 48.

Examples of the substituted silyl groups include trimethylsilyl,triethylsilyl, tripropylsilyl, tri-i-propylsilyl,dimethyl-i-propylsilyl, diethyl-i-propylsilyl,t-butylsilyldimethylsilyl, pentyldimethylsilyl, hexyldimethylsilyl,heptyldimethylsilyl, octyldimethylsilyl, 2-ethylhexyl-dimethylsilyl,nonyldimethylsilyl, decyldimethylsilyl, 3,7-dimethyloctyl-dimethylsilyl,lauryldimethylsilyl, phenyl-(C₁–C₁₂)-alkylsilyl, C₁–C₁₂alkoxyphenyl-(C₁–C₁₂)-alkylsilyl, C₁–C₁₂alkylphenyl-(C₁–C₁₂)-alkylsilyl, 1-naphthyl-(C₁–C₁₂)-alkylsilyl,2-naphthyl-(C₁–C₁₂)-alkylsilyl, phenyl-(C₁–C₁₂)-alkyldimethylsilyl,triphenylsilyl, tri-p-xylylsilyl, tribenzylsilyl, diphenylmethylsilyl,t-butyldiphenylsilyl, dimethylphenylsilyl, trimethoxysilyl,triethoxysilyl, tripropyloxysilyl, tri-i-propylsilyl,dimethyl-i-propylsilyl, methyldimethoxysilyl and ethyldimethoxysilylgroups.

The above described substituted silyloxy groups mean silyloxy groupssubstituted by one, two or three groups selected from the groupconsisting of alkyl, aryl, arylalkyl and monovalent heterocyclic groups.The number of carbons that each of the substituted silyloxy groups hasis usually about 1 to 60 and preferably 3 to 48.

Examples of the substituted silyloxy groups include trimethylsilyloxy,triethylsilyloxy, tripropylsilyloxy, tri-i-propylsilyloxy,dimethyl-i-propylsilyloxy, diethyl-i-propylsilyloxy,t-butylsilyldimethylsilyloxy, pentyldimethylsilyloxy,hexyldimethylsilyloxy, heptyldimethylsilyloxy, octyldimethylsilyloxy,2-ethylhexyl-dimethylsilyloxy, nonyldimethylsilyloxy,decyldimethylsilyloxy, 3,7-dimethyloctyl-dimethylsilyloxy,lauryldimethylsilyloxy, phenyl-(C₁–C₁₂)-alkylsilyloxy, C₁–C₁₂alkoxyphenyl-(C₁–C₁₂)-alkylsilyloxy, C₁–C₁₂alkylphenyl-(C₁–C₁₂)-alkylsilyloxy, 1-naphthyl-(C₁–C₁₂)-alkylsilyloxy,2-naphythyl-(C₁–C₁₂)-alkylsilyloxy,phenyl-(C₁–C₁₂)-alkyldimethylsilyloxy, triphenylsilyloxy,tri-p-xylylsilyloxy, tribenzylsilyloxy, diphenylmethylsilyloxy,t-butyldiphenylsilyloxy, dimethylphenylsilyloxy, trimethoxysilyloxy,triethoxysilyloxy, tripropyloxysilyloxy, tri-i-propylsilyloxy,dimethyl-i-propylsilyloxy, methyldimethoxysilyloxy andethyldimethoxysilyloxy groups.

Examples of the above described halogen atoms include fluorine,chlorine, bromine and iodine.

The number of carbons that each of the above described acyl groups hasis usually about 2 to 20 and preferably 2 to 18. Specific examples ofthe acyl groups include acetyl, propionyl, butyryl, isobutyryl,pivaloyl, benzoyl, trifluoroacetyl and pentafluorobenzoyl groups.

The number of carbons that each of the above described acyloxy groupshas is usually about 2 to 20 and preferably 2 to 18. Specific examplesof the acyloxy groups include acetoxy, propionyloxy, butyryloxy,isobutyryloxy, pivaloyloxy, benzoyloxy, trifluoroacetyloxy andpentafluorobenzoyloxy groups.

The number of carbons that each of the above described imino groups hasis usually about 2 to 20 and preferably 2 to 18. Specific examples ofthe imino groups include compounds represented by the followingstructural formulae.

The number of carbons that each of the above described amide groups hasis usually about 1 to 20 and preferably 2 to 18. Specific examples ofthe amide groups include formamide, acetamide, propionamide, butyramide,benzamide, trifluoroacetamide, pentafluorobenzamide, diformamide,diacetamide, dipropionamide, dibutyramide, dibenzamide,ditrifluoroacetamide and dipentafluorobenzamide.

The number of carbons that each of the above described imide groups hasis usually about 4 to 20 and preferably 6 to 18. Specific examples ofthe imide groups include groups represented by the following structuralformulae.

In the above formulae, Me represents a methyl group.

The term “monovalent heterocyclic group” means an atomic group derivedfrom a heterocyclic compound by removal one of hydrogens on theheterocyclic ring. The number of carbons that each of the monovalentheterocyclic groups has is usually 3 to 60 and preferably 4 to 20. Thisnumber does not include the number of carbons the substituents of theheterocyclic compound have. The term “heterocyclic compound” means anorganic compound having a ring structure in which the ring structure iscomposed of not only carbon atoms, but also a heteroatom(s) such asoxygen, sulfur, nitrogen, phosphorus and boron. Examples of monovalentheterocyclic groups include thienyl, C₁–C₁₂ alkylthienyl, pyrrolyl,furyl, pyridyl and C₁–C₁₂ alkylpyridyl. Of these groups, preferable arethienyl, C₁–C₁₂ alkylthienyl, pyrrolyl and C₁–C₁₂ alkylpyridyl groups.

The number of carbons that each of the above described substitutedcarboxyl groups has is usually about 2 to 60 and preferably 2 to 48. Theterm “substituted carboxyl group” means a carboxyl group substituted byan alkyl, aryl, arylalkyl or monovalent heterocyclic group. Specificexamples of the carboxyl groups include methoxycarbonyl, ethoxycarbonyl,propoxycarbonyl, i-propoxycarbonyl, butoxycarbonyl, i-butoxycarbonyl,t-butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl,cyclohexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl,2-ethylhexyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl,3,7-dimethyloctyloxycarbonyl, dodecyloxycarbonyl,trifluoromethoxycarbonyl, pentafluoroethoxycarbonyl,perfluorobutoxycarbonyl, perfluorohexyloxycarbonyl,perfluorooctyloxycarbonyl, phenoxycarbonyl, naphthoxycarbonyl andpyridyloxycarbonyl groups.

Of the substituents as exemplified above, the substituents containing analkyl chain(s) may be straight, branched or cyclic chains, orcombinations thereof. Examples of the substituents which are notstraight chains include isoamyl, 2-ethylhexyl, 3,7-dimethyloctyl,cyclohexyl and 4-(C₁–C₁₂)-alkylcyclohexyl. The substituents containingalkyl chains may form a ring with the tips of the two alkyl chainslinked together. Further, the methyl group or methylene group as a partof the alkyl chain may be substituted by a group containing aheteroatom, or a methyl group or methylene group substituted by one ormore fluorine atoms. Examples of such heteroatoms include oxygen, sulfurand nitrogen atoms.

R₁ in the above described formula (1) represents a hydrogen atom, or analkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl,arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substitutedamino, silyl, substituted silyl, silyloxy, substituted silyloxy ormonovalent heterocyclic group, or a halogen atom.

Specific examples of alkyl or alkoxy groups as R1 include the same alkylor alkoxy groups illustrated as the substituents of the rings D and E.

Preferably, R₁ is an alkyl, aryl, substituted amino or monovalentheterocyclic group and more preferably an aryl, substituted amino ormonovalent heterocyclic group.

The basic structures of repeating units represented by the formula (1)are as follows.

Specific examples of repeating units represented by the formula (1)include the following units.

In the above formulae, Me represents a methyl group; Ph a phenyl group;Bn a benzyl group; and Ac an acetyl group.

In order to increase the polymer solubility, shift the luminescencewavelength or increase the luminous efficiency, preferably the ring(s) Dand/or E in the above formula (1) has a substituent selected from thegroup consisting of alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio,arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino,substituted amino, silyl, substituted silyl, silyloxy and substitutedsilyloxy groups, halogen atoms, and acyl, acyloxy, imino, amide, imide,monovalent heterocyclic, carboxyl, substituted carboxyl and cyanogroups. More preferably, the substituent is selected from the groupconsisting of alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio,arylalkyl, arylalkoxy, arylalkylthio, amino, substituted amino,substituted silyl and substituted silyloxy groups, a fluorine atom, andacyl, acyloxy, amide, imide, monovalent heterocyclic, carboxyl,substituted carboxyl and cyano groups. Much more preferably, thesubstituent is an alkyl, alkoxy, alkylthio, aryloxy, arylthio,arylalkyl, arylalkoxy, arylalkylthio, amino or substituted amino group.Particularly preferably, the substituent is an alkyl, alkoxy, alkylthioor substituted amino group.

To increase the solubility of the polymer in a solvent, preferably R₁ inthe formula (1) contains a cyclic or branched alkyl chain. Alsopreferably, one or more of the substituents of the rings D and E containa straight alkyl chain or a cyclic or branched alkyl chain having 3 ormore carbon atoms.

The rings D and E are preferably aromatic hydrocarbon rings, and morepreferably benzene, naphthalene or anthracene rings.

Of the above described repeating units, those represented by thefollowing formula (2-1), (2-2), (2-3), (2-4) or (2-5) are particularlypreferable.

In order to increase the polymer solubility, shift the luminescencewavelength or increase the luminous efficiency, preferably the benzene,naphthalene or anthracene ring has one or more substituents. Preferredsubstituents are the same as those contained in the ring(s) D and/or Ein the above described formula (1). Preferably, one or more of the abovesubstituents contain a straight alkyl chain or a cyclic or branchedalkyl chain having 3 or more carbon atoms.

In the formula (2-1), (2-2), (2-3), (2-4) or (2-5), R₁ represents thesame group as in the formula (1).

Of the above described repeating units, those represented by the formula(2-1) are more preferable and those represented by the following formula(3) are particularly preferable.

In the above formula, R₁ represents the same group as in the formula(1); and R₂ and R₃ each independently represent an alkyl, alkoxy,alkylthio, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio,amino or substituted amino group.

Preferably, each of R₂ and R₃ is an alkyl, alkoxy, alkylthio orsubstituted amino group.

In the repeating units represented by the above formulae (1), (2-1) to(2-5) and (3), preferably R₁ is an alkyl, aryl, substituted amino ormonovalent heterocyclic group and more preferably an aryl, substitutedamino or monovalent heterocyclic group. Particularly preferably R₁ is aphenyl group having an alkyl group at each of 2, 4, 6 positions, adialkylamino group, or a thienyl group.

In the polymer in accordance with this invention, the amount of therepeating units represented by the formula (1) is usually 1 to 100% bymole and preferably 20 to 90% by mole of the total amount of therepeating units the polymer has.

In order to increase the intensity of fluorescence, preferably thepolymer in accordance with this invention is a copolymer of therepeating units represented by the formula (1) and each having differentsubstituents or a copolymer of the repeating units represented by theformula (1) and at least one or more kinds of repeating units other thanthose represented by the formula (1). Preferably the repeating units,other than those represented by the formula (1), which the polymer ofthis invention may contain is represented by the following formula (4),(5), (6) or (7).—Ar₁—  (4)—Ar₁—X₁—(Ar₂—X₂)_(w)—Ar₃—  (5)—Ar₁—X₂—  (6)—X₂—  (7)In the above formulae, Ar₁, Ar₂ and Ar₃ each independently represent anarylene group, a divalent heterocyclic group or a divalent group havinga metal complex structure. X₁ represents —C≡C—, —N(R₂₂)— or—(SiR₂₃R₂₄)_(y)—. X₂ represents —CR₂₀═CR₂₁—, —C≡C—, —N(R₂₂)— or—(SiR₂₃R₂₄)_(y)—. R₂₀ and R₂₁ each independently represent a hydrogenatom, or alkyl, aryl, monovalent heterocyclic, carboxyl, substitutedcarboxyl or cyano group. R₂₂, R₂₃ and R₂₄ each independently represent ahydrogen atom, or alkyl, aryl, monovalent heterocyclic or arylalkylgroup. w represents an integer of 0 to 1. y represents an integer of 1to 12.

The term “arylene group” means an atomic group formed by removal of twohydrogen atoms on the ring of an aromatic hydrocarbon. The abovedescribed arylene groups include those having a condensed ring and thoseformed by combining two or more independent benzene rings or condensedrings directly or via a group such as vinylene. The number of carbonsthat each of the arylene groups has is usually about 6 to 60 andpreferably about 6 to 20. The arylene groups optionally have asubstituent. Examples of such substituents include alkyl, alkoxy,alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy,arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino,silyl, substituted silyl, silyloxy and substituted silyloxy groups,halogen atoms, and acyl, acyloxy, imino, amide, imide, monovalentheterocyclic, carboxyl, substituted carboxyl and cyano groups.Preferably, the substituent is alkyl, alkoxy, alkylthio, aryl, aryloxy,arylthio, substituted amino, substituted silyl, substituted silyloxy ormonovalent heterocyclic group.

Examples of arylene groups include a phenylene group (e.g. formulae 1 to3 below), a naphthalenediyl group (e.g. formulae 4 to 13 below),anthracenediyl (e.g. formulae 14 to 19 below), a biphenyldiyl group(e.g. formulae 20 to 25 below), a terphenyldiyl group (e.g. formulae 26to 28 below), condensed ring compounds (e.g. formulae 29 to 35 below), afluorenediyl group (e.g. formulae 36 to 38 below), an indenofluorenediylgroup (e.g. formulae 38A to 38B below), a stilbenediyl group (e.g.formulae A to D below), and a distilbenediyl group (e.g. formulae E andF below). Of these arylene groups, preferable are phenylene,biphenyldiyl, fluorenediyl and stilbenediyl groups.

In this invention, the term “divalent heterocyclic group” means anatomic group formed by removal of two hydrogen atoms on the ring of aheterocyclic compound. The number of carbons that each of the divalentheterocyclic groups has is usually about 3 to 60 and preferably 4 to 20.The divalent heterocyclic groups optionally have a substituent.

The term “heterocyclic compound” means an organic compound having a ringstructure in which the ring structure is composed of not only carbonatoms, but also a heteroatom(s) such as oxygen, sulfur, nitrogen,phosphorus, boron and arsenic.

Examples of the substituents the divalent heterocyclic groups haveinclude alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl,arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substitutedamino, silyl, substituted silyl, silyloxy and substituted silyloxygroups, halogen atoms, and acyl, acyloxy, imino, amide, imide,monovalent heterocyclic, carboxyl, substituted carboxyl and cyanogroups. Preferably, the substituent is alkyl, alkoxy, alkylthio, aryl,aryloxy, arylthio, substituted amino, substituted silyl, substitutedsilyloxy or monovalent heterocyclic group.

Examples of the divalent heterocyclic groups are as follows:

-   divalent heterocyclic groups containing nitrogen as a heteroatom(s)    such as pyridinediyl (formulae 39 to 44 below), diazaphenylene    (formulae 45 to 48 below), quinolinediyl (formulae 49 to 63 below),    quinoxalinediyl (formulae 64 to 68 below), acridinediyl (formulae 69    to 72 below), bipyridylyl (formulae 73 to 75 below) and    phenanthrolinediyl (formulae 76 to 78 below) groups;

divalent heterocyclic groups containing silicon, nitrogen, sulfur orselenium as a heteroatom(s) and having a fluorene structure (formulae 79to 93 below);

divalent heterocyclic groups containing silicon, nitrogen, sulfur orselenium as a heteroatom(s) and having an indenofluorene structure(formulae J to O below);

five-membered heterocyclic groups containing silicon, nitrogen, sulfuror selenium as a heteroatom(s) (formulae 94 to 98 below);

five-membered ring condensed heterocyclic groups containing silicon,nitrogen, sulfur or selenium as a heteroatom(s) (formulae 99 to 110below);

five-membered heterocyclic groups containing silicon, nitrogen, sulfuror selenium as a heteroatom(s) two or more of which are combined attheir α positions to form a dimer or oligomer (formulae 111 to 112below);

five-membered heterocyclic groups containing silicon, nitrogen, sulfuror selenium as a heteroatom(s) which are combined with phenyl groups attheir α positions (formulae 113 to 119 below); and

five-membered ring condensed heterocyclic groups containing oxygen,nitrogen or sulfur as a heteroatom(s) and substituted by phenyl, furilor thienyl groups (formulae 120 to 125 below).

The term “divalent group having a metal complex structure” means adivalent group derived from a metal complex having an organic ligand byremoval of two hydrogen atoms on the ligand.

In metal complexes having an organic ligand, the number of carbons thateach of the organic ligands has is usually about 4 to 60. Examples ofsuch organic ligands include 8-quinolinol and the derivatives thereof,benzoquinolinol and the derivatives thereof, 2-phenyl-pyridine and thederivatives thereof, 2-phenyl-benzothiazole and the derivatives thereof,2-phenyl-benzoxazole and the derivatives thereof, and porphine and thederivatives thereof.

Examples of central metal atoms of metal complexes having an organicligand include aluminum, zinc, beryllium, iridium, platinum, gold,europium and terbium.

Examples of metal complexes having an organic ligand include those knownas low-molecule fluorescent materials or phosphorescent materials andso-called triplet luminescent complexes.

Examples of divalent groups having a metal complex structure include thefollowing groups (formulae 126 to 132).

In the above described formulae 1 to 132 and G to O, R eachindependently represents a hydrogen atom, or an alkyl, alkoxy,alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy,arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino,silyl, substituted silyl, silyloxy or substituted silyloxy group, or ahalogen atom, or an acyl, acyloxy, imino, amide, imide, monovalentheterocyclic, carboxyl, substituted carboxyl or cyano group.

Although a single structural formula has a plurality of Rs in the abovedescribed examples, they may represent the same group or atom ordifferent groups or atoms. To increase the solubility of the polymer ina solvent, it is preferable that at least one of the Rs in a singlestructural formula is other than hydrogen, and besides the shape ofrepeating units, including their substituents, does not have a largedegree of symmetry. It is also preferable that one or more of the Rs ina single structural formula are groups that contain a straight-chainalkyl group or a cyclic or branched-chain alkyl group having 3 or morecarbon atoms. A plurality of Rs may be linked together to form a ring.

In the substituents of the above described formulae in which at leastone R contains an alkyl group, the alkyl group may be a straight-chain,branched-chain or cyclic alkyl group, or a combination thereof. When thealkyl group is not a straight-chain one, it may be an isoamyl,2-ethylhexyl, 3,7-dimethyloctyl, cyclohexyl or4-(C1–C12)-alkylcyclohexyl group.

Further, the methyl or methylene group of the alkyl group contained inat least one R of the substituents may be replaced by a methyl ormethylene group substituted by a heteroatom or one or more fluorineatoms. Examples of such heteroatoms include oxygen, sulfur and nitrogenatoms.

When the R includes an aryl or heterocyclic group as its part, the arylor heterocyclic group may further include one or more substituents.

Of the repeating units, other than those represented by the formula (1),which the polymer of this invention may contain, those represented bythe above formulae (4) and (5) are more preferable.

Of the repeating units represented by the above formula (4), thoserepresented by the following formula (8), (9), (10), (11), (12) or (13)are preferable.

In the above formula, R₂₅ represents an alkyl, alkoxy, alkylthio, aryl,aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl,arylalkynyl, amino, substituted amino, silyl, substituted silyl,silyloxy or substituted silyloxy group, or a halogen atom, or an acyl,acyloxy, imino, amide, imide, monovalent heterocyclic, carboxyl,substituted carboxyl or cyano group; and z represents an integer of 0 to4. When more than one group or atom R₂₅ exist, they may be the same ordifferent.

Specific examples of the repeating units represented by the formula (8)are as follows.

In the above formula, R₂₆ and R₂₇ each independently represent the samegroup as the R₂₅ in the formula (8); and aa and bb each independentlyrepresent an integer of 0 to 3. When more than one group or atom R₂₆ andmore than one group or atom R₂₇ exist, they may be the same ordifferent.

Specific examples of the repeating units represented by the formula (9)are as follows.

In the above formula, R₂₈ and R₃₁ each independently represent the samegroup as the R₂₅ in the formula (8); cc and dd each independentlyrepresent an integer of 0 to 4; and R₂₉ and R₃₀ each independentlyrepresent a hydrogen atom, or an alkyl, aryl, monovalent heterocyclic,carboxyl, substituted carboxyl or cyano group. When more than one atomor group R₂₈ and more than one atom or group R₃₁ exist, they may be thesame or different.

Specific examples of the repeating units represented by the formula (10)are as follows.

In the above formula, R₃₂ represents an alkyl, alkoxy, alkylthio, aryl,aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl,arylalkynyl, amino, substituted amino, silyl or substituted silyl group,or a halogen atom, or an acyl, acyloxy, imino, amide, imide, monovalentheterocyclic, carboxyl, substituted carboxyl or cyano group; eerepresents an integer of 0 to 2; Ar₆ and Ar₇ each independentlyrepresent an arylene group, a divalent heterocyclic group or a divalentgroup having a metal complex structure; sa and sb each independentlyrepresent 0 or 1; and X₄ represents O, S, SO, SO₂, Se or Te. When morethan one group or atom R₃₂ exist, they may be the same or different.

Specific examples of the repeating units represented by the formula (11)are as follows.

In the above formula, R₃₃ and R₃₄ each independently represent the samegroup as the R₂₅ in the formula (8); ff and gg each independentlyrepresent an integer of 0 to 4; X₅ represents O, S, SO, SO₂, Se, Te,N—R₃₅ or SiR₃₆R₃₇; X₆ and X₇ each independently represent N or C—R₃₈;and R₃₅, R₃₆, R₃₇ and R₃₈ each independently represent a hydrogen atom,or an alkyl, aryl, arylalkyl or monovalent heterocyclic group. When morethan one atom or group R₃₃ and more than one atom or group R₃₄ exist,they may be the same or different.

Examples of the central five-membered rings in the repeating unitsrepresented by the formula (12) include thiadiazole, oxadiazole,triazole, thiophene, furan and silole.

Specific examples of the repeating units represented by the formula (12)are as follows.

In the above formula, R₃₉ and R₄₄ each independently represent the samegroup as the R₂₅ in the formula (8); hh and jj each independentlyrepresent an integer of 0 to 4; R₄₀, R₄₁, R₄₂ and R₄₃ each independentlyrepresent the same group as the R₂₉ in the formula (10); and Ar₅represents an arylene group, a divalent heterocyclic group or a divalentgroup having a metal complex structure. When more than one atom or groupR₃₉ and more than one atom or group R₄₄ exist, they may be the same ordifferent.

Specific examples of the repeating units represented by the formula (13)are as follows.

Of the repeating units represented by the above described formula (5),those represented by the following formula (14) are preferable.

In the above formula, Ar₁₁, Ar₁₂, Ar₁₃ and Ar₁₄ each independentlyrepresent an arylene or divalent heterocyclic group; Ar₁₅, Ar₁₆ and Ar₁₇each independently represent an aryl or monovalent heterocyclic group;and qq and rr each independently represent 0 or 1, wherein 0≦qq+rr≦1.

Specific examples of the repeating units represented by the abovedescribed formula (14) are as follows (formulae 133 to 140).

In the above formulae, R represents the same as that in the abovedescribed formulae 1 to 132 and J to O.

Of the repeating units, other than those represented by the formula (1),which are represented by the formulae (8), (9), (10), (11), (12), (13)and (14), those represented by the formula (14) is more preferable. Therepeating units represented by the following formula (14-2) areparticularly preferable.

In the above formula, R₄₅, R₄₆ and R₄₇ each independently represent analkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl,arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substitutedamino, silyl, substituted silyl, silyloxy or substituted silyloxy group,or a halogen atom, or an acyl, acyloxy, imino, amide, imide, monovalentheterocyclic, carboxyl, substituted carboxyl or cyano group; kk and mmeach independently represent an integer of 0 to 4; pp represents aninteger of 1 to 2; and nn represents an integer of 0 to 5. When morethan one atom or group R₄₅, more than one atom or group R₄₆ and morethan one atom or group R₄₇ exist, they may be the same or different.

The polymer may also include repeating units other than thoserepresented by formulae (1) to (14) as long as they do not impair thefluorescence characteristics or charge transport characteristics of thepolymer. The repeating units represented by the formulae (1) to (14) orother repeating units may be linked together by non-conjugated units.Alternatively, the repeating units may include such non-conjugatedportions. Examples of the bond-structures include those shown below andcombinations of two or more of the same. R in the bond-structuresrepresents a group selected from the group consisting of the samesubstituents as those described above in connection with R and Arrepresents a hydrocarbon group having 6 to 60 carbons.

The polymer of this invention may be a random, block or graft copolymer.Alternatively, it may be a polymer having a structure somewhere betweenrandom, block and graft copolymers; for example, it may be a randomcopolymer which assumes characteristics of a block copolymer. From theviewpoint of obtaining a light emitting polymer (a light emittingmaterial having a high-molecular-weight) that provides fluorescence orphosphorescence in high quantum yields, a random copolymer assumingcharacteristics of a block copolymer, or a block or graft copolymer ispreferable compared with a perfect random copolymer. Such copolymersinclude: those having chain branching on their backbones and 3 or moreterminals; and dendrimers.

The end groups of the polymer of this invention may be protected with astable protective group, because if polymerization activating groupsremain in the polymer, the luminescence characteristics or life of theelement formed of the polymer may be reduced. Preferable protectivegroups are those having a conjugated bond continuous with the conjugatedstructure of the polymer's backbone, for example, structures combiningwith an aryl or heterocyclic group via a carbon-carbon bond. Specificexamples of such groups include substituents described in Formula 10 inJP-A-9-45478.

The number average molecular weight, in terms of polystyrene, of thepolymer of this invention is 10³ to 10⁸ and preferably 5×10³ to 10⁶.

Good solvents for the polymer of this invention include, for example,chloroform, methylene chloride, dichloroethane, tetrahydrofuran,toluene, xylene, mesitylene, tetralin, decalin and n-butylbenzene.Normally, 0.1% by weight or more of the polymer of this invention can bedissolved in such solvents, though its depends on the structure ormolecular weight of the polymer.

Now, methods for producing the polymer of this invention will bedescribed.

The polymer of this invention can be produced by subjecting a compoundrepresented by the following formula (15), as one of its raw materials,to condensation polymerization.

In the above formula, rings D, E and R1 each represent the same asdescribed above. Y1 and Y2 each independently represent substituentsthat take part in the condensation polymerization.

Examples of substituents that take part in the condensationpolymerization include halogen atoms, and alkylsulfonate, arylsulfonate,arylalkylsulfonate, borate ester, methyl sulfonium, methyl phophonium,methyl phosphonate, methyl halide, boric acid, formyl, cyanomethyl andvinyl groups.

Alkylsulfonate groups include, for example, methanesulfonate,ethanesulfonate and trifluoromethanesulfonate groups. Arylsulfonategroups include, for example, benzenesulfonate and p-toluenesulfonategroups. And arylalkylsulfonate groups include, for example,benzylsulfonate group.

Borate ester groups include, for example, groups represented by thefollowing formulae.

In the above formulae, Me represents a methyl group and Et an ethylgroup.

Methyl sulfonium groups include, for example, groups represented by thefollowing formulae.—CH₂S⁺Me₂X⁻, —CH₂S⁺Ph₂X⁻In the above formulae, X represents a halogen atom and Ph a phenylgroup.

Methyl phosphonium groups include, for example, groups represented bythe following formula.—CH₂P⁺Ph₃X⁻In the above formula, X represents a halogen atom.

Methyl phosphonate groups include, for example, groups represented bythe following formula.—CH₂PO(OR′)₂In the above formula, R′ an alkyl, aryl or arylalkyl group.

Methyl monohalide groups include, for example, methyl fluoride, methylchloride, methyl bromide and methyl iodide groups.

Preferred substituents that take part in the condensation polymerizationreaction vary depending on the type of the polymerization reaction;however, when the reaction is the Yamamoto coupling reaction or the likewhich uses a zerovalent nickel complex, preferred substituents include,for example, halogen, alkylsulfonate, arylsulfonate andarylalkylsulfonate groups. When the reaction is the Suzuki couplingreaction or the like which uses a nickel or palladium catalyst,preferred substituents include, for example, halogen, borate ester andboric acid groups.

When the polymer of this invention further has repeating units otherthan those represented by the formula (1), the condensationpolymerization can be carried out in the presence of a compound whichhas two substituents that take part in condensation polymerization andis to be the repeating units other than those represented by the formula(1).

Examples of compounds which have substituents that take part incondensation reaction and are to be repeating units other than thoserepresented by the formula (1) include compounds represented by theformulae (16) to (19) below.

Subjecting not only the compound represented by the above describedformula (15) but also a compound represented by any one of the followingformulae (16) to (19) to condensation polymerization makes it possibleto produce a polymer that has not only the repeating units representedby the formula (1) but also one or more kinds of repeating unitsrepresented by the formula (4), (5), (6) or (7).Y₃—Ar₁—Y₄  (16)Y₃—Ar₁—X₁—(Ar₂—X₂)_(w)—Ar₃—Y₄  (17)Y₃—Ar₁—X₂—Y₄  (18)Y₃—X₂—Y₄  (19)In the above formulae, Ar₁, Ar₂, Ar₃, X₁ and X₂ each represent the sameas above. Y₃ and Y₄ each independently represent a substituent thattakes part in the condensation polymerization.

In a method for producing the polymer of this invention, any knowncondensation reaction can be used as the condensation polymerizationreaction, depending on the substituents of the above compounds (15) to(19) that take part in the condensation polymerization reaction.

Methods for producing the polymer of this invention include: forexample, polymerization of applicable monomers by the Suzuki couplingreaction or the like which uses a nickel or palladium catalyst;polymerization of applicable monomers by the Grignard reaction;polymerization of applicable monomers by the Yamamoto coupling reactionor the like which uses a zerovalent nickel complex; polymerization ofapplicable monomers using an oxidant such as FeCl₃; electrochemicaloxidative polymerization of applicable monomers; and decomposition of anintermediate polymer having an appropriate leaving group.

Methods in which condensation polymerization produces double bonds inthe polymer of this invention include, for example, those described inJP-A-5-202355. Specifically, they include: polymerization of a compoundhaving a formyl group and a compound having a methyl phosphonium groupby the Wittig reaction; polymerization of a compound having both formylgroup and methyl phosphonium group by the Wittig reaction;polymerization of a compound having a vinyl group and a compound havinga halogen atom by the Heck reaction; polycondensation of a compoundhaving two or more methyl monohalide groups by dehydrohalogenation;polycondensation of a compound having two or more methyl sulfoniumgroups by sulfonium salt decomposition; polymerization of a compoundhaving a formyl group and a compound having a cyanomethyl group by theKnoevenagel reaction; and polymerization of a compound having two ormore formyl groups by the McMurry reaction.

Methods in which condensation polymerization produces triple bonds inthe backbone of the polymer of this invention include, for example,those using the Heck reaction or the Sonogashira reaction.

Methods in which condensation polymerization produces neither doublebonds nor triple bonds in the polymer of this invention include: forexample, polymerization of applicable monomers by the Suzuki couplingreaction; polymerization of applicable monomers by the Grignardreaction; polymerization of applicable monomers using a Ni (0) complex;polymerization of applicable monomers using an oxidant such as FeCl₃;electrochemical oxidative polymerization of applicable monomers; anddecomposition of an intermediate polymer having an appropriate leavinggroup.

Of these methods, polymerization by the Suzuki coupling reaction whichuses a nickel or palladium catalyst, polymerization by the Grignardreaction, polymerization by the Yamamoto coupling reaction which uses azerovalent nickel complex, polymerization by the Wittig reaction,polymerization by the Heck reaction, polymerization by the Sonogashirareaction and polymerization of the Knoevenagel reaction are preferablebecause of ease of structural control.

The reaction conditions will be described in further detail.

In the Wittig, Horner and Knoevenagel reactions, the reactions arecarried out using the equivalent or more of, preferably one to threeequivalents of alkali to the functional groups of the compounds used.Alkalies used include, but not limited to, the following: metalalcholates such as potassium t-butoxide, sodium t-butoxide, sodiumethylate and lithium methylate; hydride reagents such as sodium hydride;and amides such as sodium amide. Solvents used include, for example,N,N-dimethylformamide, tetrahydrofuran, dioxane and toluene. Usually thereactions are allowed to progress at room temperature to about 150° C.The reaction time is, for example, 5 minutes to 40 hours; however, itmay be any time as long as the reactions fully progress. Preferably itis 10 minutes to 24 hours, because the polymerization products need notbe left for a long time after the termination of the reactions. Theconcentration of the compounds used is properly selected from the rangeof about 0.01% by weight to the maximum concentration to which thecompounds are dissolved. If the concentration is too low, the reactionis made less efficient, whereas it is too high, the reaction isdifficult to control. Usually the concentration is in the range of 0.1%by weight to 30% by weight. The details of the Witting reaction aredescribed in, for example, Organic Reactions, Vol. 14, 270–490, JohnWiley & Sons, Inc., 1965. The details of the Knoevenagel, Wittig anddehydrohalogenation reactions are described in Makromol. Chem.,Macromol. Symp., Vol. 12, 229, 1987.

In the Heck reaction, monomers are allowed to react in the presence oftriethylamine with a palladium catalyst. A solvent with a relativelyhigh boiling point, such as N,N-dimethylformamide orN-methylpyrrolidone, is used. The reaction temperature is about 80 to160° C. and the reaction time is about 1 hour to 100 hours. The detailsof the Heck reaction are described in, for example, Polymer, Vol. 39,5241–5244, 1998.

In the Sonogashira reaction, usually monomers are allowed to react inthe presence of a base, such as triethylamine, with a palladium catalystand cuprous iodide in N,N-dimethylformamide, an amine solvent or ethersolvent. Usually the reaction temperature is about −50 to 120° C. andthe reaction time is about 1 hour to 100 hours, though they depend onthe reaction conditions or the reactivity of the polymerizablesubstituents of the monomers. The details of the Sonogashira reactionare described in, for example, Tetrahedron Letters, Vol. 40, 3347–3350,1999 and Tetrahedron Letters, Vol. 16, 4467–4470, 1975.

In the Suzuki reaction, monomers are allowed to react by adding theequivalent or more of, preferably 1 to 10 equivalents of an inorganicbase such as potassium carbonate, sodium carbonate or barium hydroxide,an organic base such as triethylamine, or an inorganic salt such ascesium fluoride to the monomers and usingpalladium(tetrakis(triphenylphosphine)) or palladium acetate as acatalyst. The reaction may be carried out in a two-phase system by usingthe inorganic salt in an aqueous solution form. Solvents used include,for example, N,N-dimethylformamide, toluene, dimethoxyethane andtetrahydrofuran. The suitable reaction temperature is about 50 to 160°C., though it depends on the solvent used. The temperature may be raisedto near the boiling point of the solvent, followed by reflux. Thereaction time is about 1 to 200 hours.

The details of the Suzuki reaction are described in, for example, Chem.Rev., Vol. 95, 2457, 1995.

Methods which use a zerovalent nickel complex will be described. Themethods are divided into two types: one type is to use a zerovalentnickel complex; and the other is to react a nickel salt in the presenceof a reductant to produce zerovalent nickel in the system and to reactthe same.

Zerovalent nickel complexes used include, for example,bis(1,5-Cyclooctadiene)nickel(0),(ethylene)bis(triphenylphosphine)nickel(0) andtetrakis(triphenylphosphine)nickel. Of these zerovalent nickelcomplexes, bis(1,5-Cyclooctadiene)nickel(0) is preferable from theviewpoint of general-purpose properties and low cost.

From the viewpoint of better yield, it is preferable to add a neutralligand.

The term “a neutral ligand” means a ligand that has neither anion norcation. Examples of neutral ligands include: nitrogen-containing ligandssuch as 2,2′-bipyridyl, 1,10-phenanthroline, methylenebisoxazoline andN,N′-tetramethylethylenediamine; and tertiary phosphine ligands such astriphenylphosphine, tritolylphosphine, tributylphosphine andtriphenoxyphosphine. From the viewpoint of general-purpose propertiesand low cost, nitrogen-containing ligands are preferable, and from theviewpoint of high reactivity and high yield, 2,2′-bipyridyl isparticularly preferable. From the viewpoint of better yield of polymer,a system is particularly preferable which is obtained by adding2,2′-bipyridyl, as a neutral ligand, to a system containingbis(1,5-Cyclooctadiene)nickel(0). Nickel salts used in the methods inwhich zerovalent nickel is reacted in a system include, for example,nickel chloride and nickel acetate. Reductants used include, forexample, zinc, sodium hydride, hydrazine and the derivatives thereof,and lithium aluminum hydride. If necessary, ammonium iodide, lithiumiodide or potassium iodide is used as an additive.

Of the production methods of this invention, a method is preferable inwhich Y₁, Y₂, Y₃ and Y₄ each independently represent a halogen atom, oran alkylsulfonate, arylsulfonate or arylalkylsulfonate group andcondensation polymerization is carried out in the presence of azerovalent nickel complex.

In this case, raw material compounds used include, for example, dihalidecompounds, bis(alkylsulfonate) compounds, bis(arylsulfonate) compounds,bis(arylalkylsulfonate) compounds, halogen-alkylsulfonate compounds,halogen-arylsulfonate compounds, halogen-arylalkylsulfonate compounds,alkylsulfonate-arylsulfonate compounds,alkylsulfonate-arylalkylsulfonate compounds andarylsulfonate-arylalkylsulfonate compounds.

Of the production methods of this invention, a method is preferable inwhich Y₁, Y₂, Y₃ and Y₄ each independently represent a halogen atom, oran alkylsulfonate, arylsulfonate, arylalkylsulfonate, boric acid orborate ester group, the ratio of the total mole number (J) of thehalogen, alkylsulfonate, arylsulfonate and arylalkylsulfonate groups tothat (K) of the boric acid and borate ester groups is substantially 1(usually K/J is in the range of 0.7 to 1.2), and the condensationpolymerization is carried out using a nickel or palladium catalyst.

In this case, specific examples of combinations of the raw materialcompounds used include those of any one selected from the groupconsisting of dihalide compounds, bis(alkylsulfonate) compounds,bis(arylsulfonate) compounds and bis(arylalkylsulfonate) compounds andany one selected from the group consisting of diboric acid compounds anddiborate ester compounds. Alternatively, any one of halogeno-boric acidcompounds, halogeno-borate ester compounds, alkylsulfonate-boric acidcompounds, alkylsulfonate-borate ester compounds, arylsulfonate-boricacid compounds, arylsulfonate-borate ester compounds,arylalkylsulfonate-boric acid compounds or arylalkylsulfonate-borateester compounds is used alone as starting compound.

Generally, it is preferable to subject the organic solvent used in theproduction of the polymer of this invention to deoxygenation treatmentand allow the reaction to progress in an inert atmosphere to suppressside reactions, though it depends on the compound and reaction used. Itis also preferable to subject the solvent used to dehydration treatment.However, this does not necessarily apply to the reactions in a two-phasesystem: a solvent-water system, such as the Suzuki coupling reaction.

To allow the polymerization reaction to progress, an alkali or anappropriate catalyst may also be added. Such an alkali or catalyst canbe selected depending on the type of the reaction. Preferably, an alkalior catalyst is selected which is fully dissolved in the solvent used inthe reaction. Methods for mixing an alkali or catalyst with a reactionsolution include: for example, a method in which a solution of thealkali or catalyst is slowly added to the reaction solution withstirring in an inert atmosphere such as argon or nitrogen, and a methodin which the reaction solution is slowly added to the solution of thealkali or catalyst.

The polymerization time is usually about 0.5 to 100 hours, though itdepends on the type of polymerization. Preferably it is within 10 hoursin view of production cost.

The polymerization temperature is usually about 0 to 200° C., though itdepends on the type of polymerization. From the viewpoint of high yieldand low heating cost, preferably it is in the range of 20 to 100° C.

When using the polymer of this invention in a polymeric LED, it ispreferable to purify monomers to be used by means such as distillation,sublimation, recrystallization or column chromatography beforepolymerization, because the purity of the polymer affects the LED'sperformance such as luminescent characteristics. After polymerization,preferably the polymer undergoes purifying treatment by variousoperations including: separation in common use such as washing with anacid, washing with an alkali, neutralization, washing with water,washing with an organic solvent, reprecipitation, centrifugation,extraction, column chromatography or dialysis; purification; and drying.

Now, methods will be described for producing the compounds representedby the above described formula (15) which are used as the raw materialsfor the polymer of this invention.

Methods for producing the compounds represented by the above describedformula (15) vary depending on the type of the substituents that takepart in the condensation polymerization of the compounds. In a firsttype of methods, for example, the compounds can be produced by thereaction leading to the introduction of the substituents (Y1 and Y2)that take part in the condensation polymerization reaction intocompounds represented by the following formula (20).

In the above formula, R₁ and rings D and E each represent the same asthose in the above described formula (1).

Specific examples of the first type of methods include: a method inwhich the compounds represented by the above described formula (15)whose substituents that take part in the condensation polymerizationreaction are formyl groups are synthesized by reacting the compoundsrepresented by the above described formula (20) with a formylationreagent; a method in which the compounds represented by the abovedescribed formula (15) whose substituents that take part in thecondensation polymerization reaction are monohalogenomethyl groups aresynthesized by reducing the above formylated compounds and reacted thereduced compounds with a halognation reagent; and a method in which thecompounds represented by the above described formula (15) whosesubstituents that take part in the condensation polymerization reactionare vinyl groups are synthesized by reacting the formyl groups of theabove formylated compounds with the Wittig reagent or the Honer reagent.

The above first type of methods also include a method in which thecompounds represented by the above described formula (15) whosesubstituents that take part in the condensation polymerization reactionare monohalogenomethyl groups are synthesized by reacting the compoundsrepresented by the above described formula (20) with paraform andhydrogen halide.

Further, the above first type of methods also include a method in whichthe compounds represented by the above described formula (15) whosesubstituents that take part in the condensation polymerization reactionare halogen atoms are synthesized by reacting the compounds representedby the above described formula (20) with a halogenation reagent or byreacting the compounds represented by the above described formula (20)with a base, followed by reaction with a halogenation reagent.

Further, a method is also included in which the compounds represented bythe above described formula (15) whose substituents that take part inthe condensation polymerization reaction are boric acid groups or borateester groups are synthesized by reacting the compounds represented bythe above described formula (15) whose substituents that take part inthe condensation polymerization reaction are halogen atoms with a base,followed by the reaction with a boric acid compound. Still further, amethod is also included in which the compounds represented by the abovedescribed formula (15) whose substituents that take part in thecondensation polymerization reaction are alkylsulfonate, arylsulfonateor arylalkylsulfonate groups are synthesized by decomposing withhydrogen peroxide or the like the boric acid groups of the compoundsrepresented by the above described formula (15) whose substituents thattake part in the condensation polymerization reaction are boric acidgroups and subjecting the decomposed compounds to sulfonation.

In a second type of methods, the compounds represented by the abovedescribed formula (15) can be produced by reacting compounds havingsubstituents that take part in condensation polymerization reaction andrepresented by the following formula (21) with a boron compound.

In the above formula, Y₁, Y₂, and rings D and E each represent the sameas those in the above described formula (15). X is a halogen atom. Whenthe rings D and E each have a halogen atom as a substituent or wheneither Y₁ or Y₂ is a halogen atom, the halogen atom represented by X ismore reactive with a base or metal than the halogen atoms included inthe rings D and E or represented by Y₁ or Y₂.

Specific examples of the second type of methods include a method inwhich the compounds represented by the above described formula (15) areproduced by reacting compounds represented by the above describedformula (21) with a base, followed by the reaction with a boron compoundrepresented by the following formula (22).

In the above formula, R₁ represents the same as that in the abovedescribed formula (1). X′ represents a halogen atom or an alkoxy group.

Examples of halogenation reagents used in the production of thecompounds represented by the above described formula (15) include:N-halogeno compounds such as N-chlorosuccinimide, N-chlorophthalimide,N-chlorodiethylamine, N-chlorodibutylamine, N-chlorocyclohexylamine,N-bromosuccinimide, N-bromophthalimide, N-bromoditrifluoromethylamine,N-iodosuccinimide and N-iodophthalimide; fluorine;fluoroxytrifuluoromethane; oxygen difluoride; perchloryl fluoride;cobalt fluoride (III); silver fluoride (II); selenium fluoride (IV);manganese fluoride (III); chlorine; iodotrichloride; aluminumtrichloride; tellurium chloride (IV); molybdenum chloride; antimonychloride; iron chloride (III); titanium tetrachloride; phosphoruspentachloride; thionyl chloride; bromine; 1,2-dibromoethane; borontribromide, copper bromide; silver bromide; t-butyl bromide, bromineoxide; iodine; and iodomonochloride.

Examples of bases used in the production of the compounds include:lithium hydride, sodium hydride, potassium hydride, methyllithium,n-butyllithium, t-butyllithium, phenyllithium, lithium diisopropylamide,lithium hexamethyldisilazide, sodium hexamethyldisilazide and potassiumhexamethyldisilazide.

Examples of solvents used in the reaction include: saturatedhydrocarbons such as pentane, hexane, heptane, octane and cyclohexane;unsaturated hydrocarbons such as benzene, toluene, ethylbenzene andxylene; saturated halogenated hydrocarbons such as carbon tetrachloride,chloroform, dichloromethane, chlorobutane, bromobutane, chloropentane,bromopentane, chlorohexane, bromohexane, chlorocyclohexane andbromocyclohexane; unsaturated halogenated hydrocarbons such aschlorobenzene, dichlorobenzene and trichlorobenzene; alcohols such asmethanol, ethanol, propanol, isopropanol, butanol and t-butylalcohol;carboxylic acids such as formic acid, acetic acid and propionic acid;ethers such as dimethyl ether, diethyl ether, methyl-t-butylether,tetrahydrofuran, tetrahydropyran and dioxane; amines such astrimethylamine, triethylamine, N,N,N′,N′-tetramethylethylenediamine andpyridine; and amides such as N,N-dimethylformamide,N,N-dimethylacetoamide, N,N-diethylacetoamide and N-methylmorpholineoxide. Any single solvent or mixed solvent of two or more selected fromamong these solvents can be used depending on the reaction.

The compounds represented by the above formula (15) can be obtained byconventional post-treatment, such as quenching with water, extractionwith an organic solvent and evaporating of the solvent, after thereaction.

The isolation and purification of the products can be done by means ofseparation by chromatography or recrystallization.

The applications of the polymer of this invention will be described.

Normally the polymer of this invention fluorescences or phosphorescencesin the solid state, and it can be used as a polymeric luminous body (ahigh-molecular-weight light-emitting material). A polymer LED using thepolymeric luminous body is a high-performance polymeric LED that can bedriven at low voltage and at high efficiency. Accordingly, such apolymeric LED can be suitably used for the backlight of liquid crystaldisplays, curved-surface or flat surface light sources, segment-typedisplay devices, or units such as dot matrix flat panel displays.

The polymer of this invention can also be used as a laser dye, materialfor organic solar cells, organic semiconductor for organic transistor,material for conductive thin film such as conductive thin film andorganic semiconductor thin film.

Further, the polymer of this invention can also be used as a materialfor light-emitting thin films that emit fluorescence or phosphorescence.

The polymeric LED of this invention will be described.

The polymeric LED of this invention is characterized in that it has anorganic layer between electrodes: an anode and a cathode, which containsthe polymer of this invention.

The organic layer may be a light-emitting layer, a hole transport layeror an electron transport layer; however, it is preferably alight-emitting layer.

The term “a light-emitting layer” means a layer having the function ofemitting light, the term “a hole transport layer” means a layer havingthe function of transporting holes, and the term “an electron transportlayer” means a layer having the function of transporting electrons. Theelectron transport layer and the hole transport layer are genericallycalled charge transport layer. The polymeric LED may include tow or moreof each of the light-emitting layer, hole transport layer and electrontransport layer.

When the organic layer is a light-emitting layer, the light-emittinglayer as an organic layer may further include a hole transport material,an electron transport material or a light-emitting material. The term “alight-emitting material” means a material that fluorescences and/orphosphorescences.

When mixing the polymer of this invention and a hole transport material,the hole transport material mixed constitutes 1% by weight to 80% byweight and preferably 5% by weight to 60% by weight of the entiremixture. When mixing the polymer of this invention and an electrontransport material, the electron transport material mixed constitutes 1%by weight to 80% by weight and preferably 5% by weight to 60% by weightof the entire mixture. And when mixing the polymer of this invention anda light-emitting material, the light-emitting material mixed constitutes1% by weight to 80% by weight and preferably 5% by weight to 60% byweight of the entire mixture. When mixing the polymer of this invention,a light-emitting material, and a hole transport material and/or anelectron transport material, the fluorescent material mixed constitutes1% by weight to 50% by weight and preferably 5% by weight to 40% byweight of the entire mixture, the sum of the hole transport material andthe electron transport material mixed constitutes 1% by weight to 50% byweight and preferably 5% by weight to 40% by weight of the entiremixture, and the content of the polymer of this invention is 99% byweight to 20% by weight.

For the hole transport material, the electron transport material and thelight-emitting material, a well-known low-molecular-weight compound orpolymeric compound can be used; however, preferably a polymeric compoundis used. Examples of the polymeric hole transporting, electrontransporting and light-emitting materials include: polyfluorene and thederivatives and copolymers thereof; polyarylene and the derivatives andcopolymers thereof; polyarylenevinylene and the derivatives andcopolymers thereof; and (co)polymers of aromatic amines and theirderivatives which are disclosed in, for example, WO 99/13692, WO99/48160, GB2340304A, WO 00/53656, WO 01/19834, WO 00/55927, GB2348316,WO 00/46321, WO 00/06665, WO 99/54943, WO 99/54385, U.S. Pat. No.5,777,070, WO 98/06773, WO 97/05184, WO 00/35987, WO 00/53655, WO01/34722, WO 99/24526, WO 00/22027, WO 00/22026, WO 98/27136, U.S. Pat.No. 5,736,36, WO 98/21262, U.S. Pat. No. 5,741,921, WO 97/09394, WO96/29356, WO 96/10617, EP0707020, WO 95/07955, JP-A-2001-181618,JP-A-2001-123156, JP-A-2001-3045, JP-A-2000-351967, JP-A-2000-303066,JP-A-2000-299189, JP-A-2000-252065, JP-A-2000-136379, JP-A-2000-104057,JP-A-2000-80167, JP-A-10-324870, JP-A-10-114891, JP-A-9-111233 andJP-A-9-45478.

Examples of applicable low-molecular-weight light-emitting materialsinclude: naphthalene derivatives; anthracene or the derivatives thereof;perylene or the derivatives thereof; dyes such as polymethine, xanthene,coumarin and cyanine; metal complexes of 8-hydroxyquinoline or thederivatives thereof; aromatic amines; tetraphenylcyclopentadiene or thederivatives thereof; or tetraphenylbutadiene or the derivatives thereof.

Specifically, well-known low-molecular-weight light-emitting materialssuch as those described in JP-A-57-51781 and JP-A-59-194393 can be used.

Examples of triplet luminous complexes include: Ir(ppy)₃ andBtp₂Ir(acac) with iridium as the central metal atom; PtOEP with platinumas the central metal atom; and Eu(TTA)3phen with europium as the centralmetal atom.

Specific examples of triplet luminous complexes include those describedin Nature (1998), 395, 151, Appl. Phys. Lett. (1999), 75(1), 4, Proc.SPIE-Int. Soc. Opt. Eng. (2001), 4105 (Organic Light-Emitting Materialsand Devices IV), 119, J. Am. Chem. Soc. (2001), 123, 4304, Appl. Phys.Lett. (1997), 71(18), 2596, Syn. Met. (1998), 94(1), 103, Syn. Met.(1999), 99(2), 1361, Adv. Mater., (1999), 11(10), 852, and Jpn. J. Appl.Phys. 34, 1883 (1995).

The composition of this invention contains: at least one kind ofmaterial selected from the group consisting of hole transport, electrontransport and light-emitting materials; and the polymer of thisinvention. The composition can be used as a light-emitting material oran electron transport material.

The content ratio of at least one kind of material selected from thegroup consisting of hole transport, electron transport andlight-emitting materials to the polymer of this invention can bedetermined depending on the application of the composition. However,when the composition is used as a light-emitting material, preferablythe content ratio is the same as that of the above describedlight-emitting layer.

For the film thickness of the light-emitting layer the polymeric LED ofthis invention has, its optimum value varies depending on the materialused, and therefore it can be selected so that the values of the drivingvoltage and luminous efficiency of the polymeric LED become proper ones.For example, the thickness is 1 nm to 1 μm, preferably 2 nm to 500 nm,and more preferably 5 nm to 200 nm.

Methods for forming the light-emitting layer include, for example,formation of the layer from a solution. Examples of such methods includecoating methods such as spin coating, casting, micro gravure coating,gravure coating, bar coating, roll coating, wire bar coating, dipcoating, spray coating, screen printing, flexographic printing, offsetprinting and ink-jet printing. Printing methods such as screen printing,flexographic printing, offset printing and ink-jet printing arepreferable because they make pattern forming or multicolor coatingeasier.

The ink compositions used in printing methods may be any compositions aslong as they contain at least one kind of polymer of this invention.They may also contain a hole transport material, an electron transportmaterial, a light-emitting material, a solvent, or additives such as astabilizer.

The polymer of this invention contained in the above ink compositionconstitutes 20% by weight to 100% by weight and preferably 40% by weightto 100% by weight of the entire ink composition excepting its solvent.

When the ink composition contains a solvent, the solvent constitutes 1%by weight to 99.9% by weight, preferably 60% by weight to 99.5% byweight and more preferably 80% by weight to 99.0% by weight of theentire composition.

Preferred viscosity of the ink composition varies depending on theprinting method employed; however, when the method employed is ink-jetprinting or the like in which the ink composition passes through an inkejecting device, preferably the viscosity is in the range of 1 to 20mPa·s at 25° C. to prevent the ink from clogging or losing straightnessof droplet jetting on its ejection.

The solvents used in the ink composition may be any solvents; however,preferably they can uniformly dissolve or disperse the materials, otherthan the solvent, that constitute the ink composition. When thematerials constituting the ink composition are soluble in non-polarsolvents, such solvents include: for example, chlorine solvents such aschloroform, methylene chloride and dichloroethane; ether solvents suchas tetrahydrofuran; aromatic hydrocarbon solvents such as toluene andxylene; ketone solvents such as acetone and methyl ethyl ketone; andester solvents such as ethyl acetate, butyl acetate and ethyl cellosolveacetate.

The polymeric LEDs of this invention include: for example, a polymericLED including an electron transport layer between the cathode and thelight-emitting layer; a polymeric LED including a hole transport layerbetween the anode and the light-emitting layer; and a polymeric LEDincluding an electron transport layer between the cathode and the lightemitting layer and a hole transport layer between the anode and thelight-emitting layer.

Specific examples of the polymeric LED structures include the followinga) to d).

-   a) anode/light-emitting layer/cathode-   b) anode/hole transport layer/light-emitting layer/cathode-   c) anode/light-emitting layer/electron transport layer/cathode-   d) anode/hole transport layer/light-emitting layer/electron    transport layer/cathode    (The slash “/” indicates the layers are laminated adjacent to each    other. This applies to any “/” below.)

When the polymeric LED of this invention has a hole transport layer, thehole transport material applicable is, for example, polyvinylcarbazoleor a derivative thereof; polysilane or a derivative thereof; apolysiloxane derivative having aromatic amine on its side chain orbackbone; a pyrazoline derivative; an arylamine derivative; a stilbenederivative; a triphenyldiamine derivative; polyaniline or a derivativethereof; polythiophene or a derivative thereof; polypyrrole or aderivative thereof; poly(p-phenylenevinylene) or a derivative thereof;or poly(2,5-thienylenevinylene) or a derivative thereof.

Specific examples of the hole transport materials include thosedescribed in JP-A-63-70257, JP-A-63-175860, JP-A-2-135359,JP-A-2-135361, JP-A-2-209988, JP-A-3-37992 and JP-A-3-152184.

Of these hole transport materials used for the hole transport layer,preferable is a polymeric hole transport material such aspolyvinylcarbazole or a derivative thereof; polysilane or a derivativethereof; a polysiloxane derivative having aromatic amine on its sidechain or backbone; polyaniline or a derivative thereof; polythiophene ora derivative thereof; poly(p-phenylenevinylene) or a derivative thereof;or poly(2,5-thienylenevinylene) or a derivative thereof. And morepreferable is polyvinylcarbazole or a derivative thereof; polysilane ora derivative thereof; or a polysiloxane derivative having aromatic amineon its side chain or backbone.

Specific examples of hole transport materials of low molecular weightinclude pyrazoline derivatives, arylamine derivatives, stilbenederivatives, and triphenyldiamine derivatives. When using alow-molecular-weight hole transport material, it is preferable todisperse it in a polymeric binder.

As the polymeric binder to be mixed, one which does not extremelyinhibit the electron transportation and does not have strong absorptionof visible light is preferably used. Such a polymeric binder is, forexample, poly(N-vinylcarbazole), polyaniline or a derivative thereof,polythiophene or a derivative thereof, poly(p-phenylenevinylene) or aderivative thereof, or poly(2,5-thienylenevinylene) or a derivativethereof, polycarbonate, polyacrylate, polymethylacrylate,polymethylmethacrylate, polystyrene, polyvinyl chloride, orpolysiloxane.

Polyvinylcarbazole or a derivative thereof can be derived from a vinylmonomer by cationic polymerization or radical polymerization.

Examples of polysilane or the derivatives thereof include the compoundsdescribed in Chem. Rev. Vol. 89, 1359, 1989 or GB 2300196. As methodsfor synthesizing such compounds, those described in the above documentscan be used. Of the methods, Kipping method is particularly preferablyused.

For polysiloxane or the derivatives thereof, since the siloxane backbonestructure hardly show hole transporting properties, those having astructure of the above described low-molecular-weight hole transportmaterial on their side chains or backbone are preferably used. Suchpolysiloxane or derivatives thereof include those having aromatic amine,which is a hole transport material, on their side chains or backbones.

Film forming methods for the hole transporting layer are not limited toany specific ones. However, when using a low-molecular-weight holetransport material, methods are used in which the film is formed from amixed solution of the material and a polymeric binder. When using apolymeric hole transport material, methods are used in which the film isformed from a solution of the material.

Solvents used in the methods for forming the layer from a solution maybe any solvents as long as they can dissolve hole transport materials.Examples of such solvents include chlorine solvents such as chloroform,methylene chloride and dichloroethane; ether solvents such astetrahydrofuran; aromatic hydrocarbon solvents such as toluene andxylene; ketone solvents such as acetone and methyl ethyl ketone; andester solvents such as ethyl acetate, butyl acetate and ethyl cellosolveacetate.

Examples of applicable methods for forming the layer from a solutioninclude spin coating, casting, micro gravure coating, gravure coating,bar coating, roll coating, wire bar coating, dip coating, spray coating,screen printing, flexographic printing, offset printing and ink-jetprinting.

The optimum value of the thickness of the hole transport layer variesdepending on the material used, and therefore it can be selected so thatthe values of the driving voltage and luminous efficiency of thepolymeric LED are reasonable. However, the layer needs to be so thick atleast not to form pinholes therein; but on the other hand, too thicklayer is not preferable because the driving voltage of the elementincreases. Accordingly, the thickness of the hole transport layer is,for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and morepreferably 5 nm to 200 nm.

When the polymeric LED of this invention has an electron transportlayer, well known compounds can be used as the electron transportmaterials. Such a compound is, for example, a metal complex of: anoxadiazole derivative; anthraquinodimethane or a derivative thereof;benzoquinone or a derivative thereof; naphthoquinone or a derivativethereof; anthraquinone or a derivative thereof;tetracyanoanthraquinodimethane or a derivative thereof; a fluorenonederivative; diphenyldicyanoethylene or a derivative thereof; or adiphnoxy derivative; 8-hydroxyquinoline or a derivative thereof,polyquinoline or a derivative thereof, polyquinoxaline or a derivativethereof, or polyfluorene or a derivative thereof.

Specific examples of the electron transport materials include thosedescribed in JP-A-63-70257, JP-A-63-175860, JP-A-2-135359,JP-A-2-135361, JP-A-2-209988, JP-A-3-37992 and JP-A-3-152184.

Of these electron transport materials used for the electron transportlayer, preferable are metal complexes of: oxadiazole derivatives;benzoquinone or the derivatives thereof; anthraquinone or thederivatives thereof; 8-hydroxyquinoline or the derivative thereof,polyquinoline or the derivatives thereof, polyquinoxaline or thederivatives thereof, or polyfluorene or the derivatives thereof. Morepreferable are 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole,benzoquinone, anthraquinone, tris(8-quinolinol)aluminum, andpolyquinoline.

Film forming methods for the electron transporting layer are not limitedto any specific ones. However, when using a low-molecular-weightelectron transport material, methods are used in which the film isformed from a powder of the material by vacuum deposition or from asolution of the material or the material in the molten state. When usinga polymeric electron transport material, methods are used in which thefilm is formed from a solution of the material or the material in themolten state. When forming the film from a solution of a material or amaterial in the molten state, any one of the above described polymericbinders may be used together.

Solvents used in the methods for forming the layer from a solution maybe any solvents as long as they can dissolve electron transportmaterials and/or polymeric binders. Examples of such solvents includechlorine solvents such as chloroform, methylene chloride anddichloroethane; ether solvents such as tetrahydrofuran; aromatichydrocarbon solvents such as toluene and xylene; ketone solvents such asacetone and methyl ethyl ketone; and ester solvents such as ethylacetate, butyl acetate and ethyl cellosolve acetate.

Examples of applicable methods for forming the layer from a solution ofthe material or the material in the molten state include spin coating,casting, micro gravure coating, gravure coating, bar coating, rollcoating, wire bar coating, dip coating, spray coating, screen printing,flexographic printing, offset printing and ink-jet printing.

The optimum value of the thickness of the electron transport layervaries depending on the material used, and therefore it can be selectedso that the values of the driving voltage and luminous efficiency of thepolymeric LED are reasonable. However, the layer needs to be so thick atleast not to form pinholes therein; but on the other hand, too thicklayer is not preferable because the driving voltage of the elementincreases. Accordingly, the thickness of the electron transport layeris, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, and morepreferably 5 nm to 200 nm.

Of the charge transport layers provided adjacent to electrodes, thosehaving the function of improving the efficiency of charge injection fromthe electrodes and of reducing the driving voltage of the element aresometimes referred to as charge injection layer (hole injection layer,electron injection layer).

To improve the adhesion to electrodes or improve the charge injectionfrom the electrodes, the above described charge injection layer or aninsulating layer 2 nm or less thick may be provided adjacent to eachelectrode. Further, to improve the adhesion between interfaces orprevent the mixture of the same, a thin buffer layer may be inserted ineach interface of the electron transport layer and the light-emittinglayer.

The order, number and thickness of the layers laminated may be selectedtaking into consideration the luminous efficiency or life time of theelement.

Examples of the polymeric LEDs of this invention provided with a chargeinjection layer(s) (an electron injection layer (s), a hole injectionlayer (s)) include: those provided with a charge injection layeradjacent to the cathode and those provided with a charge injection layeradjacent to the anode.

Specific examples include the following structures e) to p).

-   e) anode/charge injection layer/light-emitting layer/cathode-   f) anode/light-emitting layer/charge injection layer/cathode-   g) anode/charge injection layer/light-emitting layer/charge    injection layer/cathode-   h) anode/charge injection layer/hole transport layer/light-emitting    layer/cathode-   i) anode/hole transport layer/light-emitting layer/charge injection    layer/cathode-   j) anode/charge injection layer/hole transport layer/light-emitting    layer/charge injection layer/cathode-   k) anode/charge injection layer/light-emitting layer/electron    transport layer/cathode-   l) anode/light-emitting layer/electron transport layer/charge    injection layer/cathode-   m) anode/charge injection layer/light-emitting layer/electron    transport layer/charge injection layer/cathode-   n) anode/charge injection layer/hole transport layer/light-emitting    layer/electron transport layer/cathode-   o) anode/hole transport layer/light-emitting layer/electron    transport layer/charge injection layer/cathode-   p) anode/charge injection layer/hole transport layer/light-emitting    layer/electron transport layer/charge injection layer/cathode

Specific examples of the charge injection layers include: a layer thatcontains a conductive polymer; a layer that is provided between theanode and a hole transport layer and contains a material having anionization potential between that of the anode material and that of thehole transport material contained in the hole transport layer; and alayer that is provided between the cathode and an electron transportlayer and contains a material having an electron affinity between thatof the cathode material and that of the electron transport materialcontained in the electron transport layer.

When the above described charge injection layer is a layer that containsa conductive polymer, the electric conductivity of the conductivepolymer is preferably 10⁻⁵ S/cm or more and 10³ S/cm or less. Todecrease the leak current among light-emitting pixels, the electricconductivity is preferably 10⁻⁵ S/cm or more and 10² S/cm or less andmore preferably 10⁻⁵ S/cm or more and 10¹ S/cm or less.

Usually, an appropriate amount of ion is doped into the conductivepolymer to keep the electric conductivity of the same 10⁻⁵ S/cm or moreand 10³ S/cm or less.

The kind of the ion doped is anion when the charge injection layer is ahole injection layer, while it is cation when the charge injection layeris an electron injection layer. Examples of the anions includepolystrenesulfonic acid ion, alkylbenzenesulfonic acid ion andcamphosulfonic acid ion. Examples of the cations include lithium ion,sodium ion, potassium ion and tetrabutylammonium ion.

The thickness of the charge injection layer is, for example, 1 nm to 100nm and preferably 2 nm to 50 nm.

The materials used for the charge injection layers can be properlyselected taking into consideration the materials of the electrodes andtheir adjacent layers. The materials include: for example, conductivepolymers such as polyaniline and the derivatives thereof; polythiopheneand the derivatives thereof; polypyrrole and the derivatives thereof;polyphenylenevinylene and the derivatives thereof;polythienylenevinylene and the derivatives thereof; polyquinoline andthe derivatives thereof; polyquinoxaline and the derivatives thereof;and polymers having an aromatic amine structure on their backbones orside chains, metal phthalocyanine (copper phthalocyanine), and carbon.

The insulating layer 2 nm or less thick has the function of makingcharge injection easy. Examples of the materials for the insulatinglayer include metal fluorides, metal oxides and organic insulatingmaterials. Examples of the polymeric LEDs provided with an insulatinglayer(s) 2 nm or less thick include: those provided with an insulatinglayer 2 nm or less adjacent to the cathode and those provided with aninsulating layer 2 nm or less adjacent to the anode.

Specific examples include the following structures q) to ab).

-   q) anode/insulating layer 2 nm or less thick/light-emitting    layer/cathode-   r) anode/light-emitting layer/insulating layer 2 nm or less    thick/cathode-   s) anode/insulating layer 2 nm or less thick/light-emitting    layer/insulating layer 2 nm or less thick/cathode-   t) anode/insulating layer 2 nm or less thick/hole transport    layer/light-emitting layer/cathode-   u) anode/hole transport layer/light-emitting layer/insulating layer    2 nm or less thick/ cathode-   v) anode/insulating layer 2 nm or less thick/hole transport    layer/light-emitting layer/insulating layer 2 nm or less    thick/cathode-   w) anode/insulating layer 2 nm or less thick/light-emitting    layer/electron transport layer/cathode-   x) anode/light-emitting layer/electron transport layer/insulating    layer 2 nm or less thick/cathode-   y) anode/insulating layer 2 nm or less thick/light-emitting    layer/electron transport layer/insulating layer 2 nm or less    thick/cathode-   z) anode/insulating layer 2 nm or less thick/hole transport    layer/light-emitting layer/electron transport layer/cathode-   aa) anode/hole transport layer/light-emitting layer/electron    transport layer/insulating layer 2 nm or less thick/cathode-   ab) anode/insulating layer 2 nm or less thick/hole transport    layer/light-emitting layer/electron transport layer/insulating layer    2 nm or less thick/cathode

The substrate that constitutes the polymeric LED of this invention maybe any substrate as long as it does not undergo changes when electrodesor organic layers are formed on it. Examples of such substrates includeglass, plastic, polymeric film and silicon substrates. When thesubstrate is not transparent, preferably the electrode opposite to thesubstrate is transparent or semitransparent.

Usually, at least any one of the anode and cathode the polymeric LED ofthis invention has is transparent or semitransparent. Preferably, theanode is transparent or semitransparent.

As the material for the anode, a conductive metal oxide film, asemitransparent metal thin film or the like is used. Specifically, afilm (e.g., NESA) formed of a conductive glass comprising indium-oxide,zinc oxide, tin oxide, and any of their complexes, such as indium tinoxide (ITO) and indium zinc oxide, or gold, platinum, silver or copperis used. ITO, indium zinc oxide and tin oxide are preferable materials.Examples of the methods for forming the anode include vacuum deposition,sputtering, ion plating and plating. An organic transparent conductivefilm such as polyaniline or a derivative thereof or polythiophene or aderivative thereof may also be used as the anode.

The film thickness of the anode can be properly selected taking intoconsideration the light transmittivity and the electrical conductivity.It is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and morepreferably 50 nm to 500 nm.

To make charge injection easy, a layer composed of a phthalcyaninederivative, a conductive polymer or carbon, or a layer composed of ametal oxide, a metal fluoride or an organic insulating material whoseaverage thickness is 2 nm or less may be provided on the anode.

As the materials for the cathode used in the polymeric LED of thisinvention, low work-function materials are preferable. Examples of suchmaterials include: metals such as lithium, sodium, potassium, rubidium,cesium, beryllium, magnesium, calcium, strontium, barium, aluminum,scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium,terbium, ytterbium; the alloys of two or more of the above metals or thealloys of one or more of the above metals with at least one selectedfrom gold, silver, platinum, copper, manganese, titanium, cobalt,nickel, tungsten or tin; and graphite or graphite intercalationcompounds. Examples of the alloys include magnesium-silver,magnesium-indium, magnesium-aluminum, indium-silver, lithium-aluminum,lithium-magnesium, lithium-indium and calcium-aluminum alloys. Thecathode is allowed to have a laminated structure of two or more layers.

The film thickness of the cathode can be properly selected taking intoconsideration the electrical conductivity and the durability. It is, forexample, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably50 nm to 500 nm.

Examples of the methods for forming the cathode include vacuumdeposition, sputtering, and laminating in which a metal thin film is hotpressing. A layer composed of a conductive polymer or a layer composedof a metal oxide, a metal fluoride or an organic insulating materialwhose average thickness is 2 nm or less may be provided between thecathode and the organic layer. After the formation of the cathode, aprotective layer for protecting the polymeric LED may also be mounted onthe cathode. To use the polymeric LED stably and for a long time, it ispreferable to mount a protective layer and/or a protective cover on thecathode to protect the element from the outside.

For the protective layer, a polymer, metal oxide, metal fluoride ormetal boride can be used. For the protective cover, a glass sheet or aplastic sheet whose surface has undergone low water-permeabilitytreatment can be used. A method is preferably used in which the abovedescribed protective cover and the element substrate are tightly adheredwith a thermo-set resin or photo-set resin. If a space is kept using aspacer, it is easy to prevent the element from being damaged. If aninert gas such as nitrogen or argon is included in the space, it ispossible to prevent the cathode from being oxidized. If a desiccatingagent such as barium oxide is placed in the space, it is easy tosuppress the element from being damaged by water adsorbed on it duringthe production process. Preferably, any one or more of the means areemployed.

The polymeric LED can be used as a surface light source, segment displayunit, dot matrix display unit, or the backlight of a liquid crystaldisplay unit.

To obtain surface light emission using the polymeric LED of thisinvention, a surface anode and a surface cathode should be arranged sothat they are superposed. To obtain patterned light emission, a methodis employed in which a mask with a patterned window is provided on thesurface of the surface light-emitting element, in which the organiclayer of the non-light-emitting portion is formed to be extremely thickso that the portion does not substantially emit light, or in whicheither anode or cathode or both of them are formed to have a pattern. Ifany one of the above method is employed to from a pattern and someelectrodes are arranged so that they can be each independently set atON/OFF, a segment display unit that can display numerals, letters orsimple signs is obtained. To produce a dot matrix display unit, bothanodes and cathodes are formed in stripes and arranged so that they lieat right angles to each other. A method in which polymeric luminous bodywith more than one kind of luminescent color is color-coded or a methodin which a color filter or fluorescence conversion filter is used makespossible partial color display or multicolor display. Dot matrixelements can be passive-matrix ones, or if they are combined with TFT,they can be active-matrix elements. These display elements can be usedas display units of computer, televisions, hand-held PCs, mobole phones,car navigation systems, or view finders of video cameras.

Further, since the above described surface light-emitting devices arespontaneous-emission-thin-type elements, they can be suitably used asthe surface light source for the backlight of liquid crystal displayunits or the light source for surface lighting. If a flexible substrateis used, they can be used as curved light sources or curved displayunits.

In the following, this invention will be described in detail by means ofexamples. However, the examples are not intended to limit the scope ofthis invention.

The number average molecular weight herein shown was obtained in termsof polystyrene by gel permeation chromatography (GPC) using chloroformas a solvent.

SYNTHETIC EXAMPLE 1 Synthesis of2,2′-dibromo-5,5′-dioctyloxy-1,1′-biphenyl

3,3′-dioctyloxy-1,1′-biphenyl as a raw material was synthesized by theoctylation of 3-bromophenol in ethanol, followed by the Yamamotocoupling reaction.

133 g of 3,3′-dioctyloxy-1,1′-biphenyl synthesized as above wasdissolved in 1820 ml of dried N,N-dimethylformamide. A solution of 117.5g of N-bromosuccinimide in 910 ml of N,N-dimethylformamide was addeddropwise at 0° C. (in a dry ice-methanol bath) over 60 minutes. Aftercompletion of the addition, the mixture was brought to room temperatureand stirred over night.

The reaction solution was poured into water, extracted with n-hexane,followed by evaporating of the solvent to yield 179 g of crude product.Recrystallyzation of the crude product was repeated with 2-propanol toyield 122 g of 2,2′-dibromo-5,5′-dioctyloxy-1,1′-biphenyl.

¹H-NMR (300 MHz/CDCl₃): δ (ppm)=0.88 [t, 6H], 1.2–1.8 [m, 24H], 3.95 [t,4H], 6.7–6.8 [m, 4H], 7.52 [d, 2H],

SYNTHETIC EXAMPLE 2 Synthesis of2,2′-diiodo-5,5′-dioctyloxy-1,1′-biphenyl

4.05 g of chipped magnesium was put in a 500 ml three-neck flask in anatmosphere of nitrogen. A solution of 45 g of2,2′-dibromo-5,5′-dioctyloxy-1,1′-biphenyl synthesized as above in 200ml of tetrahydrofuran was prepared in another flask, and 20 ml of thesolution was added to the flask containing magnesium. Five drops of1,2-dibromoethane as an initiator was added to the magnesium mixture andheated. Once an exothermic reaction was initiated, the rest of thesolution was added dropwise to the mixture over 30 minutes. Aftercompletion of the addition of the solution, the reaction was allowed toprogress under reflux for 1 hour. Then, the reaction solution was cooledto 0° C., and a solution of 44.2 g of iodine in 150 ml oftetrahydrofuran was added dropwise. After completion of the addition,the reaction solution was stirred at room temperature overnight.

The reaction solution was poured into water, extracted with chloroform,followed by washing with an aqueous solution of sodium thiosulfate and asaturated salt solution. Then, the reaction solution was dried withsodium sulfate, followed by evaporating the solvent to yield 53 g ofcrude product. The crude product was recrystallyzed with 2-propanol toyield 43 g of 2,2′-diiodo-5,5′-dioctyloxy-1,1′-biphenyl.

¹H-NMR (200 MHz/CDCl₃): δ (ppm)=0.90 [t, 6H], 1.2–1.8 [m, 24H], 3.93 [t,4H], 6.6–6.8 [m, 4H], 7.74 [d, 2H],

MS (APCL (+)): M⁺ 662.

SYNTHETIC EXAMPLE 3 Synthesis of4,4′-dibromo-2,2′-diiodo-5,5′-dioctyloxy-1,1′-biphenyl

37 g of 2,2′-diiodo-5,5′-dioctyloxy-1,1′-biphenyl synthesized as abovewas put in a 1 L flask in an atmosphere of nitrogen and 800 ml oftrimethyl phosphate was added to dissolve the same. Then, 10.6 g ofiodine was added and a solution of 19 g of bromine in 70 ml of trimethylphosphate was added dropwise. After 4-hour stirring, a solution of 9.5 gof bromine in 35 ml of trimethyl phosphate was added dropwise to themixture. After completion of the addition of the solution, the mixturewas stirred overnight. The reaction solution was poured into water,extracted with chloroform, followed by washing with an aqueous solutionof sodium thiosulfate and a saturated salt solution. Then, the reactionsolution was dried with sodium sulfate, followed by evaporating thesolvent to yield 46 g of crude product. The crude product was purifiedby silica gel chromatography (cyclohexane toluene=20:1) to yield 20.5 gof 4,4′-dibromo-2,2′-diiodo-5,5′-dioctyloxy-1,1′-biphenyl.

¹H-NMR (200 MHz/CDCl₃): δ (ppm)=0.88 [t, 6H], 1.2–1.9 [m, 24H], 3.99 [m,4H], 6.70 [s, 2H], 8.03 [s, 2H],

MS (APCl (+)): M⁺ 820.

SYNTHETIC EXAMPLE 4 Synthesis of3,7-dibromo-5-(2,4,6-triisopropylphenyl)-2,8-dioctyloxy-5H-dibenzo(b,d)borole

2.0 g of 4,4′-dibromo-2,2′-diiodo-5,5′-dioctyloxy-1,1′-biphenylsynthesized as above was put in a 100 ml flask in an atmosphere ofnitrogen and 20 ml of tetrahydrofuran was added to dissolve the same.Then, the tetrahydrofuran solution was cooled to −90° C. and 3.4 ml of1.6M hexane solution was added dropwise. After 1-hour stirring, asolution of 1.5 g of magnesium bromide in 20 ml of tetrahydrofuran wasadded, warmed to room temperature, and stirred for 1 hour. The mixturewas cooled again to −90° C., and 1.01 g of(2,4,6-triisopropylphenyl)dimethoxyborane was added. After warming, themixture was allowed to react under reflux for 12 hours.

After evaporating the solvent, the resultant product was purified twiceby silica gel chromatography (cyclohexane/toluene) to yield 0.47 g of3,7-dibromo-5(2-4-6-triisopropylphenyl)-2,8-dioctyloxy-5H-dibenzo(b,d)borole.

¹H-NMR (200 MHz/CDCl₃): δ (ppm)=0.89 [t, 6H], 1.1–1.6 [m, 38H], 1.89 [m,4H], 2.44 [m, 2H], 2.93 [m, 1H], 4.17 [t, 4H], 6.89 [s, 2H], 7.01 [s,2H], 7.50 [s, 2H],

MS (APCl (+)) : M⁺ 781.

EXAMPLE 1 (Condensation Polymerization) Synthesis of Polymer 1

0.41 g of3,7-dibromo-5-(2,4,6-trimethylphenyl)-2,8-dioctyloxy-5H-dibenzo(b,d)borole, 0.15 g ofN,N′-bis(4-bromophenyl)-N,N′-bis(4-n-butylphenyl)-1,4-phenylenediamineand 0.55 g of 2,2′-bipyridyl were put in a reactor, and the reactionsystem was purged with argon gas. 40 ml of tetrahydrofuran (dehydrationsolvent) having been subjected to bubbling by argon gas to be deaeratedin advance was added to the mixture. Then, 1.0 g ofbis(1,5-Cyclooctadiene)nickel(0) was added to the mixed solution,stirred at room temperature for 10 minutes, and allowed to react at 60°C. for 3 hours. The reaction was carried out in an atmosphere ofnitrogen.

After the reaction, the reaction solution was cooled, and poured into amixed solution of 100 ml of methanol/200 ml of ion-exchanged water,followed by stirring for about 1 hour. Then, the precipitate wasfiltered, dried under reduced pressure, and dissolved in 40 ml oftoluene. After that, 40 ml of 1N hydrochloric acid was added, and themixed solution was stirred for 1 hour. After removing the water layer,40 ml of aqueous ammonia was added to the organic layer and stirred for1 hour, and the water layer was removed. The resultant solution waspurified through an alumina column, the recovered toluene solution wasadded dropwise to 200 ml of methanol and stirred, and the precipitatewas filtered and dried under reduced pressure for 2 hours. The polymeryield was 20 mg. The polymer was referred to as polymer 1.

The number average molecular weight and the weight average molecularweight, in terms of polystyrene, of the polymer 1 was 6.1×10³ and9.9×10³, respectively.

EXAMPLE 2

A thin film of the polymer 1 was formed by spin-coating a 0.2% by weightchloroform solution of the polymer 1 onto quartz. The fluorescentspectrum of the thin film was measured using a fluorescencespectrophotometer (Hitachi Ltd.: 850). The polymer 1 has intensefluorescence and the fluorescence peak was at a wavelength of 564 nm.

INDUSTRIAL APPLICABILITY

The polymer of this invention is a novel polymer that can be used as alight-emitting material or a charge transport material and be used inink compositions or polymeric light-emitting devices.

1. A polymer characterized by comprising a repeating unit represented by the following formula (1) and having a number average molecular weight, in terms of polystyrene, of 10³ to 10⁸:

wherein R₁ represents a hydrogen atom, or an alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino, silyl, substituted silyl, silyloxy, substituted silyloxy or monovalent heterocyclic group, or a halogen atom; and rings D and E each independently represent an optionally substituted aromatic ring.
 2. The polymer according to claim 1, wherein the aromatic ring is an aromatic hydrocarbon ring or a heteroaromatic ring.
 3. The polymer according to claim 2, wherein the aromatic ring is an aromatic hydrocarbon ring.
 4. The polymer according to claim 2, wherein the aromatic hydrocarbon ring is a benzene, naphthalene or anthracene ring.
 5. The polymer according to claim 4, wherein the repeating unit represented by the formula (1) is represented by the following formula (2-1), (2-2), (2-3), (2-4) or (2-5):

wherein R₁ represents the same group as that in the formula (1).
 6. The polymer according to claim 1, wherein the repeating unit is represented by the following formula (3):

wherein R₁ represents the same group as that in the formula (1); R₂ and R₃ each independently represent an alkyl, alkoxy, alkylthio, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, amino or substituted amino group.
 7. The polymer according to claim 1, further comprising a repeating unit represented by the following formula (4), (5), (6) or (7): —Ar₁—  (4) —Ar₁—X₁—(Ar₂—X₂)_(w)—Ar₃—  (5) —Ar₁—X₂—  (6) —X₂—  (7) wherein Ar₁, Ar₂ and Ar₃ each independently represent an arylene group, a divalent heterocyclic group or a divalent group having a metal complex structure; X₁ represents —C≡C—, —N(R₂₂)— or —(SiR₂₃R₂₄)_(y)—; X₂ represents —CR₂₀═CR₂₁—, —C≡C—, —N(R₂₂)— or —(SiR₂₃R₂₄)_(y—; R) ₂₀ and R₂₁ each independently represent a hydrogen atom, or an alkyl, aryl, monovalent heterocyclic, carboxyl, substituted carboxyl or cyano group; R₂₂, R₂₃ and R₂₄ each independently represent a hydrogen atom, or an alkyl, aryl, monovalent heterocyclic or arylalkyl group; w represents an integer of 0 to 1; and y represents an integer of 1 to
 12. 8. The polymer according to claim 7, wherein the repeating unit represented by the formula (4) is represented by the following formula (8), (9), (10), (11), (12) or (13):

wherein R₂₅ represents an alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino, silyl, substituted silyl, silyloxy substituted silyloxy group, or a halogen atom, or an acyl, acyloxy, imino, amide, imide, monovalent heterocyclic, carboxyl, substituted carboxyl or cyano group; and z represents an integer of 0 to 4;

wherein R₂₆ and R₂₇ each independently represent the same group as the R25 in the formula (8); and aa and bb each independently represent an integer of 0 to 3;

wherein R₂₈ and R₃₁ each independently represent the same group as the R₂₅ in the formula (8); cc and dd each independently represent an integer of 0 to 4; and R₂₉ and R₃₀ each independently represent a hydrogen atom, or an alkyl, aryl, monovalent heterocyclic, carboxyl, substituted carboxyl or cyano group;

wherein R₃₂ represents an alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino, silyl or substituted silyl group, a halogen atom, or an acyl, acyloxy, imino, amide, imide, monovalent heterocyclic, carboxyl, substituted carboxyl or cyano group; ee represents an integer of 0 to 2; Ar₆ and Ar₇ each independently represent an arylene group, a divalent heterocyclic group or a divalent group having a metal complex structure; sa and sb each independently represent 0 or 1; and X₄ represents O, S, SO, SO₂, Se or Te;

wherein R₃₃ and R₃₄ each independently represent the same group as the R₂₅ in the formula (8); ff and gg each independently represent an integer of 0 to 4; X₅ represents O, S, SO, SO₂, Se, Te, N—R₃₅ or SiR₃₆R₃₇; X₆ and X₇ each independently represent N or C—R₃₈; and R₃₅, R₃₆, R₃₇ and R₃₈ each independently represent a hydrogen atom, or an alkyl, aryl, arylalkyl or monovalent heterocyclic group; and

wherein R₃₉ and R₄₄ each independently represent the same group as the R₂₅ in the formula (8); hh and jj each independently represent an integer of 0 to 4; R₄₀, R₄₁, R₄₂ and R₄₃ each independently represent the same group as the R₂₉ in the formula (10); and Ar₅ represents an arylene group, a divalent heterocyclic group or a divalent group having a metal complex structure.
 9. The polymer according to claim 7, wherein the repeating unit represented by the formula (5) is represented by the following formula (14):

wherein Ar₁₁, Ar₁₂, Ar₁₃ and Ar₁₄ each independently represent an arylene or divalent heterocyclic group; Ar₁₅, Ar₁₆ and Ar₁₇ each independently represent an aryl or monovalent heterocyclic group; and qq and rr each independently represent 0 or 1, wherein 0≦qq+rr≦1.
 10. A method for producing the polymer according to claim 1, comprising subjecting a compound represented by the following formula (15), as one of its raw materials, to condensation polymerization:

wherein rings D, E and R₁ each independently represent the same as described in claim 1; Y₁ and Y₂ each independently represent a substituent that takes part in the condensation polymerization.
 11. A method for producing the polymer according to claim 7, comprising subjecting not only the compound represented by the following formula (15) but also a compound represented by any one of the following formula (16) to (19) to condensation polymerization:

wherein R₁ represents a hydrogen atom, or an alkyl, alkoxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, arylalkenyl, arylalkynyl, amino, substituted amino, silyl, substituted silyl, silyloxy, substituted silyloxy or monovalent heterocyclic group, or a halogen atom; rings D and E each independently represent an optionally substituted aromatic ring; and Y₁ and Y₂ each independently represent a substituent that takes part in the condensation polymerization; Y₃—Ar₁——Y₄  (16) Y₃—Ar₁—X₁—(Ar₂—X₂)_(w)—Ar₃—Y₄  (17) Y₃—Ar₁—X₂—Y₄  (18) Y₃—X₂—Y₄  (19) wherein Ar₁, Ar₂, Ar₃, w, X₁ and X₂ each represent the same as described above; and Y₃ and Y₄ each independently represent a substituent that takes part in the condensation polymerization.
 12. The method according to claim 11, wherein Y₁, Y₂, Y₃ and Y₄ each independently represent a halogen atom, or an alkylsulfonate, arylsulfonate or arylalkylsulfonate group and the condensation polymerization is carried out using a zerovalent nickel complex.
 13. The method according to claim 11, wherein Y₁, Y₂, Y₃ and Y₄ each independently represent a halogen atom, or an alkylsulfonate, arylsulfonate, arylalkylsulfonate, boric acid or borate ester group, the ratio of the total mole number of the halogen atom and the alkylsulfonate, arylsulfonate and arylalkylsulfonate groups to that of the boric acid and borate ester groups is substantially 1, and the condensation polymerization is carried out using a nickel or palladium catalyst.
 14. A composition, comprising: at least one material compound selected from the group consisting of a hole transport material, an electron transport material and a light-emitting material; and at least one polymer according to claim
 1. 15. An ink composition, comprising the polymer according to claim
 1. 16. The ink composition according to claim 15, having a viscosity of 1 to 20 mpa·s at 25° C.
 17. A light-emitting thin film, comprising the polymer according to claim
 1. 18. A conductive thin film, comprising the polymer according to claim
 1. 19. An organic semiconductor thin film, comprising the polymer according to claim
 1. 20. A polymeric light-emitting device, comprising a layer that comprises the polymer according to claim 1 between an anode and a cathode.
 21. The polymeric light-emitting device according to claim 20, wherein the layer that comprises the polymer is a light-emitting layer.
 22. The polymeric light-emitting device according to claim 21, wherein the light-emitting layer further comprises a hole transport material, an electron transport material or a light-emitting material.
 23. A surface light source, comprising the polymeric light-emitting device according to claim
 20. 24. A segment display unit, comprising the polymeric light-emitting device according to claim
 20. 25. A dot matrix display unit, comprising the polymeric light-emitting device according to claim
 20. 26. A liquid crystal display unit, comprising the polymeric light-emitting device according to claim 20 as its back light. 